I have used Eva-Dry units before. The ones that use silicon pellets and when full, you plug into the wall, so a little heater runs and dries them. They are OK for a cabinet or fridge, but not that much.
The calcium chloride products work fairly well. I like the Eva-Dry containers, and I make sure they are placed in a spill resistant tub or five gallon bucket. This way, I have at least two layers of protection, should I forget to remove the tubs before moving my RV. I also like having one in my bathtub as well.
If I close up the rig, the air doesn't move that much inside, so multiple large containers of CaCl2 do the job well enough to reduce smells.
Of course, the ideal would be to have a dehumidifier draining into a sink, with the gray tank valve screened (so no bugs/rats go up the exit.) However, CaCl2 is better than nothing.