Actually, you shouldn't have any smell at all from the toilet. If you do, there's something wrong. The commode has a water tight (hence airtight as well) seal that is closed when not in use. There should also be pink antifreeze in the toilet bowl to keep the seals from drying out and shrinking. The liquid provides yet another barrier for odors.
The first thing to check is the toilet model. There are a lot of Dometic 300 toilets that trap flushed water inside the hollow body. If you have a Dometic model 300, contact Dometic and they will ship you a new toilet right away. No questions asked.
If you do not have a Dometic 300, then you may have a leak. I'd recommend removing the toilet, clean the floor area around and underneath the toilet thoroughly (checking for water damage), then clean the toilet outside. Once completely cleaned, go ahead and reinstall. This should solve your stinky toilet problem.
Now, if your problem is not a stinky toilet, but is, in fact, a stinky black water tank, there are a couple things to check there, as well.
First is the vent pipe. This pipe sticks up through the roof, so once you find it up there, you can pretty much figure out where it goes through the bathroom (usually the sink cabinet). With the water supply off, open the toilet seal by holding the flush lever open, have somebody on the roof blowing air down the tube, and listen for air in the black tank. The air can be supplied by a leaf blower. This will ensure that the vent is clear and that the air is going into the tank and not somewhere else (vent disconnected).
A thorough flushing of the black tank is probably in order, as well. Fill it at least 1/4 full of water (just stick a garden hose in the toilet) or use a flushing wand (preferred). Stick the wand down the throat of the toilet and move it around a lot to direct the spray to every corner of the tank. Be generous with the water and give it time to work. Ensure all solids are rinsed out of the tank then add a few gallons of clean water to the tank and toss in whatever your preferred deodorant chemical might be.
A clean, empty tank does not have a noticeable smell. I have never used any kind of chemicals in my tanks. My last TT was 23 years old when I got rid of it, and had no noticeable odor. I "simply" ensured that the tanks were completely flushed after each use. The only liquid in them between uses was pink antifreeze. I make a habit of pouring antifreeze into the toilet and the p-traps between uses to keep seals lubricated.
2022 Keystone Cougar 24RDS
2023 Ram 6.7L Laramie Mega Cab
