I have to agree with Stu.
I realize getting rid of waste especially in fresh water with limited pump out facilities can be daunting.
Also, what works for one, may not work for another but, I personally, have no desire to leave my boat while composting is happening. Give me a good waste tank anytime. It's not my wish to lug sh*t pellets all the time either. My boat trash only contains cans, plastic & paper, not poop.
In addition, the pellets are not really trash material, but waste.
CR