Here is the routine I have developed over many snowbird winters.
1. Get a clear sight adapter and put it between the trailer and the sewer hose.
2. I leave the black tank closed for a week at a time. Grey tanks open.
3. I form a pee trap in the sewer hose with a couple boards, one 2x and a 4x4.
4. To dump and flush, I remove the pee trap boards.
5. Close the grey water tanks.
6. Open the black water tank and turn on the hose to the built in flush system.
7. Watch the sight tube until I am down to just hose water coming out.
8. Go inside and do two full bowl super flushes. "Bomb the Pile!" Note: Full bowl means filling the bowl to the bottom of the upper rim.
9. Go back outside and view discharge.
10. Close the black water tank and run the flush water in for four(4) minutes. Do not let anyone distract you at this point.
11. Open and drain and repeat 10 again.
12. Flush a bit and verify that you have nice clear water coming out of the tank. If not go back to step 8 and start again.
13. When you have nice clear discharge, put the pee trap boards back the sewer line and fill the pee trap.
14. Close the black water tank and add about a minute worth of water to the tank with the flush hose.
15. Secure the flush hose. I have a little inline valve adapter at the side of the trailer and the other end gets turned off.
16. Open the grey water tanks and go add your chemical to the tank.
I have had the burping a couple of times, however the super flushes seem to have fixed that issue.
Having piles in not good!!
Chris