Well I don't know if there is something specific about your camper model, but they all have pretty much the same tank and toilet AFAIK.
I've been using a product called OdoBan available at Sams, Walmart, Home Depot, etc. Comes in 1 gallon jugs. After dumping/rinsing the tank ... I fill the black tank with 2-3 gallons of water and a 1/2 - 1 cup of OdoBan. I'll throw a little in the grey tank too just in case. If that get's real "funky" that can get about as bad as the black tank. So far no smells and it's a lot cheaper then "traditional" RV chemicals.
OdoBan - Odor Eliminator - Home
"Best Chemicals to use" is hotly debated on here, be ready for a wide array of suggestions.