Several years ago and have posted comments from time to time when the subject came-up, just like it came up here now. Peggie's comments about the liquid disposal are a big concern because it really does not take very long for the bottle to fill-up. As for smells, I have never had a problem. In fact, my test was to stick my own head into the toilet to "sample" the smells. The really HUGE problem with a composting head is coming to light, when you sail for a long period of time on the wrong tack. The result? There is no longer a separation of liquids and solids and you will smell THAT fast. For that reason, I took my composting head off of the boat and sold it to catamaran owner.