Take the money you spend foolishly on black tank chemicals and buy one of
THESE or you can go to Walmart and get one without the gate attached.
Use plenty of water during each flush, keep the toilet paper usage to a minimum and don't be skimpy with the water. When the tank is about 2/3rds full, using the above device (or your in-tank rinse) and add more water until 3/4ers full and then drain. Once drained, add more water and drain again.
You do NOT need chemicals....water is more than sufficient to keep the tank free from clogs. If you have an odor, then you have a problem that needs to be repaired.
Hope this helps
Ron