Recycling Greywater + Biodegradable Soaps

If you’re thinking about recycling your greywater, either in your tiny house or other home on wheels, you need to pay attention to what’s going down the drain.

Recycling greywater (which is the used water from showers, the sink, and the washer machine) requires us to be conscientious of what we put down our drains, since those products will end up in our gardens, yards, and in the ground.

A welcome side effect of being careful about which products end up in our drains is that we know more about which soaps, cleaners and detergents we are using in our homes and on our bodies. Using all-natural cleaners and body products is better for your health and the environment.

So If you’re designing your tiny home or other trailer to be off-grid, or at least want to recycle greywater, these are the things I recommend which I use in the COMET.

If you’re living in a trailer/ camper like me, another great by-product of recycling greywater is that you don’t have to dump greywater tanks out at dump stations or RV parks, which is gross. I specifically designed the COMET to not have any grey or black water tanks, because I am recycling and composting all “wastes” (which become something much nicer than waste because I’m reusing them!).

By being careful and conscientious about what we put on our bodies and down our drains, we can keep water of of the sewers and put it safely back into the land. I’ve gotten a few questions about this topic recently, so I hope this clarifies it for you!

(Disclaimer: some of these links are affiliate links, meaning that at no extra cost to you, if you decide to purchase something I recommend I get a small commission, which helps keep this blog up and running! Thank you!)


Tea - Tea is naturally slightly acidic and can replace your toxic household surface cleaners. You can use it to wipe down counters, clean off fixtures, anything really. Just make a cup of green tea and use it to wipe down surfaces in your home. Compost the tea bag and you’re golden!

Vinegar -  Tougher than tea, regular old vinegar will kill any bacteria and will clean any surface. Dilute the vinegar with water, put it in a little spray bottle, and go to town. There is honestly no reason to ever need any other type of home cleaning product. Windex and all that is absolute poison. Vinegar works better, won’t kill you or harm your pets, and is something you’ll use around the house for many reasons.

Mrs. Meyers Surface Scrub - If you really need a tough cleaner, or something with a little grit for getting honey or sticky syrup off of your counters, use this stuff. I highly recommend it. It smells freakin’ amazing and works great. Scrub down pots and pans with stuff stuck on them, or just use is once in a while in the kitchen for a deep clean.

I also recommend the Mrs. Meyer’s dishwasher liquid, which I use in the COMET. I currently use the Lavender scent, but I am also obsessed with Honeysuckle and Geranium.



Method - This is one of the very few products currently Cradle To Cradle certified (if you haven’t read Cradle to Cradle and you’re interested in how things are made, and the future of sustainable manufacturing, I recommend it. It was my introduction to sustainable design and really influenced the way I think now about planning for recycling from the start of a design). Method makes all sorts of cleaners, but I use their hand soap. Totally biodegradable, as are all of the items on this list, so you don’t have to worry about it going down the drain. If you are not a fan of scented soap, I recommend Method products because they are very mild.

Mrs. Meyers Hand Soap - This, on the other hand, is “aroma-therapeutic”, and very scented. I am obsessed with the way these smell. It seriously is therapeutic, I’m not exaggerating. I love the Lavender, Geranium, and Honeysuckle, but Basil is nice too. If you want to be the person smelling your hands throughout the day because it makes you feel nice, use this. Matt thinks I’m weird because he’ll catch me huffing my scented hands after washing them, but he just doesn’t get it!

Camp Soap - Can’t forget about the camp soap! The most basic soap on the list, nothing fancy but does the job well. Originally designed for (duh) camping and therefore always biodegradable, camp soap is cheap and odorless. It’s usually concentrated in a little bottle so you don’t need to use very much, and you're supposed to dilute with water.



Seventh Generation - I used this laundry detergent for years. It works nicely. It’s not super-scented like the regular laundry detergent I was used to, but it turns out that stuff actually destroys your clothes because of all the chemicals. This stuff is gentle and natural, and makes it so you can use your wash water out in the garden after!

Method  - When I first went to college this is what I took with me. I like that it comes in a tiny bottle, which can make a big difference if you’re living in a tiny house or camper. One skilly little bottle (which also has a nifty squirt pump top) does loads and loads, because you use just one squirt. Again, Method products are Cradle to Cradle certified, which is a very high standard for green products.

Body Care:

Dr. Bronners - I’ve been using Bronners as my main body soap/shampoo/everything for many years. When I lived in a punk house we bought it in 5 gallon buckets (to share between 12 people). It says you can use it as a toothpaste (and that is can be used for 18 other things) but I tried that once and it was not pleasant. Stick to using it as soap and shampoo and you should be all set. Dr. Bronners is a castile soap, which means it is NOT anti-bacterial. Anti-bacterial soaps are actually bad for you and contribute to more germs (and indiscriminately kills the good germs), if that makes me sound a little kooky I apologize, but I don’t use antibacterial soap anymore. The only downside to using Bronner’s castile soap is that it is harsh if you have sensitive skin. It can potentially be too dry for you. I used it as shampoo when I had really short hair, but now that my hair is longer I need something with a little more moisture. I like the Lavender scent. It also makes a great hand soap.

Trader Joe’s Citrus shampoo + conditioner - Though I still use Bronner’s for a lot of stuff, I prefer to use something more moisturizing in my hair. I like Trader Joe’s stuff because it’s affordable (haha I WISH I could afford Aveda all-natural products, but I don’t have $40 for a shampoo bottle!). It also smells nice and works well.

Mrs. Meyers Bar Soap - Now, if you're in the shower and want to smell amazing for the rest of the day, use the Mrs. Meyer’s bar soap. Smells so good Matt started using it. As I mentioned, I’m obsessed with the Geranium scented one.



I hope this guide demystifies the do’s and don’ts of using biodegradable products in your home, so that you can be informed about recycling greywater.

Not having a grey water tank is a joy, and it’s so easy to just empty my greywater at the base of tree without worries. I love being able to take outdoor showers without worrying about what I’m putting into the ground below me. The truth is, we should all be using 100% natural biodegradable stuff in our homes and on our bodies anyway, because it’s much better for our health.

When we visited Laura Lavoie ( last year, I loved her simple, gravity fed greywater system.

When we visited Laura Lavoie ( last year, I loved her simple, gravity fed greywater system.

(Disclaimer: some of these links are affiliate links, meaning that at no extra cost to you, if you decide to purchase something I recommend I get a small commission, which helps keep this blog up and running! Thank you!)