I'm on septic, and yah that's a big concern for me.
Sometimes it just makes sense to replace old drain pipes in the house that are giving you the trouble.
It's an expense for sure, but it's a heck of a lot cheaper than dealing with a non-functioning septic system somewhere down the road because you doused it with chemicals.
If you're gonna do it despite the good advice, at least time it so that you have the system pumped shortly after you pour that crap down your drains.
Алекс says don't drink and derive