One of the things we do, is to dump some beef liver down the toilette every month or so, 2 lbs is usually a good amount. This keeps the right bacteria working and properly fed.
Our most recent success with this was at my daughters place this summer. Got a desperate call saying that her septic was overflowing outside and they couldn't even take a shower with a flood outside, no inside problems thank goodness.
I told her to dump some liver into the tank and we would be up in a week or so to see what could be done.
They have a cottage in cottage country with a small tank, about 50 gal and a 2nd tank about 25 gal. They had it pumped but were back to the same issue the next day.
Well we went up there, set up a sump pump system to help out and added about 3 lbs of liver. There were other precautions and issues, so we couldn't do much else, but basically they had no flow to the bed. The ground was too hard and dry to try to dig anything, so the sump system into the bush was going to have to do for a time,,,,,
They used the pump 2 times and after that had flow again, not much, but it ran away.
This fall they dug up the run to the bed where the moisture was coming up and found that the clay tile had collapsed, but it had enough of a hole to be able to get some flow. It's now repaired and flowing real nice, with a monthly addition of BEEF liver.