Every time we tow our hybrid when we get to the site or get home we had a bad sewer odor in the camper. Just open windows and turn on the fan and its gone in a few minutes. I've tried towing with the ...
filling the black tank with water is nice, but remember to recharge with septic chemical as well. Also, if you are able to, toss in a bag of ice before you hit the road. All the sloshing around does a good job of cleaning off the sides of the tank. Finally, discourage the family from depositing 'solid' waste if possible. The residue is soooo tough to get rid of completely, and as soon as it gets wet, it can really get ripe.