I recently upgraded our single tumbling compost bin to this exact double tumbling compost bin hoping to correct some mistakes we made when we started our first compost pile. (Disclosure: I am including affiliate links for your convenience.)
The mistakes we made weren’t horrible and we did create usable compost that turned our practically all clay tan colored garden beds to earthworm rich dark black soil. But the compost coming out of the bin has always been soggy. It was also full of plastic bits we thought would compost but didn’t break down.
How did this happen? Well for one, since we don’t have access to grass clippings or leaves we used shredded paper and cardboard for brown matter (and any sawdust I made in the garage) and we simply didn’t add enough. The fix for wet or smelly compost is to always have more dry brown matter in your compost pile than green matter (vegetable and fruit peels, coffee grounds, etc.) As for the plastic bits, we’d just empty the entire contents of our home office paper shredder into the compost bin and all of those window envelopes I shredded thinking they would break down because they are made from cellulose where actually some sort of plastic.
There was finished compost in the bottom of the single compost bin but because it stopped turning and we couldn’t mix it very well with one of those compost turner things that look like this. Our compost was a big wet clump full of unwanted bits that I could easily save by sifting the almost finished compost and chucking a ton of this exact wood chip pet bedding into one side of the new compost bin and let it break down. Adding more shredded paper and cardboard boxes would also do the trick but I didn’t have enough of either in the quantity I needed at the time.