I have a home built in the mid 80s on a very sloped lot with a 1000 gallon septic tank and connected to two seepage wells. The seepage wells basically were not draining adequately, and normally were full and almost full most of the time, and rarely overflowed. I tried the aero-stream system which did no good. The septic tank empty truck operator recommended adding muriatic acid, as well as the local plumbing company who were giving an estimate to build a new septic system. I read EVERYTHING I could find on adding muriatic acid (concentrated hydrochloric acid) to septic systems, and the overwhelming advice was that it does not work, and would destroy the bacterial flora in the system.
After realizing the system was failed or very near to failure, I figured I had very little to lose. Additionally, my system was organized that the liquid effluent would flow by gravity from the septic tank to one seepage well, and once that one filled, into a second well. In other words, the acid in the seepage wells probably would not really flow into the septic tank to destroy the flora.
After having the septic tank and the two seepage wells pumped out, I added two (1) gallon bottles of muriatic acid to each seepage well and let it sit for 36 hours. I then filled each seepage well with water (with the thought of placing hydrostatic pressure on any clogs). Low and behold, one of the wells was totally drained after 1 hour!!!! The other well however showed very little drainage.
I am not suggesting ANYONE else do what I did. I am only relating my personal experience with my system. It worked fantastically on the one clogged seepage well, and fortunately, my system works great for my home (for now) I was told by the plumbers that this type of treatment generally works for a year or two, and then may clog again.