rotten egg smell

I sort of like We Cant Wait's method, except we use PineSol instead of bleach. A cup or so of PineSol poured down the sinks, a few ounces in each sink and shower. Then run fresh water to fill the grey tank...DO NOT GO FOR A WALK, don't ask. Stick around and watch the gauges to reach a full tank. Since you can't go for a drive, let it sit for a couple of hours...now you can go for that walk. Then flush the grey. Most of the odor is probably from fats stuck in the traps, these break down into butyric acid and similar stuff, some might be from the tank. Just for the heck of it, check your batteries, they can be exhausting gasses, but I doubt it since it happens when you dump, Also check the back of the propane frig, if you see yellow powder you have a problem, and the smell is the Ammonia gasses from the coolant, again, probably not, but check anyway. Oh, one more thing...make sure somebody has not set up a nest in the grey water vent pipe on top of the coach. A nest, or leafy trash will block the air flow and cause the vapors to back up. Good Luck.