Yahoo Message Number: 17004 (http://groups.yahoo.com/neo/groups/Country-Coach-Owners/conversations/messages/17004)
Much has been written of reducing odors from black water tank. I think the main point has been missed. don't let the odor into coach; do not push the toilet pedal longer than needed!. No odor comes up while the drain valve is full of falling liquids & solids. Soon as the down flow is not covering the valve, bad odors will come up. Close the valve soon as practical.
I always open the valve wide. When the solids have gone, the valve is closing and when the last colored water has gone the valve is near full shut. Then I lift the pedal to admit rinse water to bowl. After adding rinse water a quick down stroke on pedal dumps the rinse water.
ECO-save has been recommended, my coach came with a bottle of ECO-save.
We still add a bit of that bottle maybe twice a month. We do not try to get the tank completely empty or poison it or rinse it as we do not want to kill the bacteria from the ECO-save. The tank odor is pleasant compared to other tank odors we have experienced.