In my opinion, after owning a TM for 3 years (16,000+ miles) the only chemical that works is Thetford's Blue. ;D Some people don't like it because (1) it is a formaldehyde base, and/or (2) the "perfumed" aroma is stronger than they like. :'( My experience is that you either get a strong perfumed aroma or the "sewer odor." :-/ I prefer the perfumed aroma. :
I tried Thetford's Green to move away from the formaldehyde (environmentally safer) but found it's odor control to be less than the Blue.
I have tried others that didn't control odor as well as the Thetford Green. I can live with Thetford's Green product, but still prefer the Blue.
Whatever you do, DO NOT use any product other than Thetford in your commode. The rubber seals (and I assume other internal rubber parts) can be adversely affected by some to the other products and cause the rubber to deteriorate. I replaced 2 EZ-Slide valves on mine because the neoprene seals failed, most likely due to the non-Thetford chemicals I used.
