I always put about 5 gallons of water and the chemical into the black tank through the hopper. If your wife objects to a chemical smell, wait until she smells it without! Just kidding. Traveling will help aggitate the solids and liquids. Low liguids, slow drainage. To help keep it clean etc., prior to going on a trip, we dump our ice-maker box into the black tank just before we leave. The ice will clean the inside of the tank from motion, and will melt. Don't mix different chemical's try to stay with one kind. Use a biodegradable tissue, or RV tissue, don't throw anything else down there, like paper towels, napkins, garbage, etc. Just human waste, and tissue.
On the hot water heater, make sure it is full of water,(pushing out the safety valve) prior to igniting. Most newer trailers have bypass valves, for winterizing. You want to drain the hotwater heater in winter for storage, then turn the 2-way bypass valves when installing the RV antifreeze.
I would not drink the water without first sanitizing the water system with bleach, per instructions in your manual. You did not mention a manual. All the trailers I've owned had a book, and booklets for each appliance in the trailer. Read it and get familiar with eveything prior to setting. Do a dry run at home. IE: sleep in it plug it in etc. then there won't be any surpises on the road. Enjoy your new home.
Tom McCauley (DP Member #513)
"Tankers-ToyII" Loaded 05 D/A K-3500 CC, SRW. Deep pan on Allison w/Transyn. Edge Juice w/attitude, 4" Kennedy exhaust, 98 Gal. Transfer-Flow cross bed fuel tank, Leer 100XQ bed cap. Reese 14,000lb class V hitch w/ dual cam HP sway control. Tow 34ft. 32FKD Holiday Rambler travel trailer. GCW 20,360lbs