Black Tank Odor

[The_Works]

We purchased a used 2013 Winnebago Meridian MH about 6 months ago and I can not get the odor from the black tank from getting into the bathroom when we flush the toilet. I have flushed the tank thoroughly several times and just about every time I dump. I've added smelling packets to the tank and I add a liquid break down stuff I purchase from Walmart to the tank after flushing. We've driven 7K miles and during our travels I've left water and tank cleaner in about 1/3 of the tank thinking the sloshing around of the cleaner and water will clean the tank out but it hasn't. I'm thinking about getting a shop vac on the roof and try and blow air down the vent pipe but other than that I'm out of ideas and this is why I'm putting this out, what can I do!!? We full time and currently are work camping. Thanks for your helpful suggestions. Be safe out there.

[GordonThree]

You'll deffinately want to make sure the vent pipe doesn't have a nest or something in it, blocking air flow. Also make sure it doesn't have any broken connections, sometimes builders forget to glue pipe connections together.

It's impossible to eliminate smell completely, and the human nose is very very very sensitive to the smell of fecal matter.

Avoid having any vent fans on when you flush, they will draw air down the vent pipe, through the black tank and out the toilet. When the wind is just right, even having the skylight open in my bathroom is enough to draw air from the toilet.