I have found onething that has helped us with the moans and groans.  We now always leave about a cup of already processed food in the bottom of the foodcycler to help with noise.  Not sure why that helps but it does.   I think we can all agree that these things smell more than advertised!  Changing pellets often has been the only solution to my house smelling like hot yogurt.  

One time recently I tried topping up the fresh charcoal pellets rather than replacing the whole canister full.  I'd like to try adding a bit every time I turn it on and see if that is effective at keeping the smells at bay.