I think septic conditions differ greatly, depending upon where one lives. When I lived in the Texas gulf area, the soul was hard packed sand. So hard packed, that a grease trap was mandatory, to avoid clogging.
Where I live now, the soil in a gravel/loam. The gravel of course, is glacial deposit..and the loam is fertility built up over the millennial.
Septic tanks require little maintenance. In 1999, when I set up anew the place where I live today, I installed a 1500 gallon tank with 4@, 30' leech lines. Of course there was just the wife and me, but in 2014 I had it pumped "just in case"...I may have been premature in doing that..
Years ago, when a new tank was installed, folks would usually break up a cake of yeast and flush it down. They claimed it did the trick ! I don't know....