I always turn the toilet valve off and flush before driving. No slosh from the tank or the bowel. No smell from the toilet thanks to the built in P trap of the house toilet. Add blue RV treatment chemical tank to the bowel to hide the yellow color. These are the same ways we learned when CA had a water shortage years ago before I moved out.
I know that that's just a typo but I've got an office full of people who came running when I howled!!!!