I have found that I can clean anything with Castrol Super Clean, diluted slightly stronger than the directions. It's about $5.00 a GALLON at WalMart Auto Dept. I found out about it through the Vintage Airstream forum. It is good for cleaning the vinyl walls in trailers, fiberglass or about anything. Spread a mini-blind out on an outside table, spray it with diluted Castrol Super Clean, and just see the dirt come off. Hose it down thoroughly, to rinse, and you've got a clean blind.
As for cleaning holding tanks, they say the easiest way is to put a squirt of regular (not antibacterial) Dawn in the emptied tank, then 2 bags of ice, (1 bag for small holding tanks)and go travelling down the road. Your tank will be be all clean when you get to dump again. It will also clean your sensors, if you have them.
I just can't see having a bunch of different products, to carry around, when one or two will do.