quote; (1) Does this material really work?
(2) Is is safe for my septic tank?
1. Not likely, but if it does, it would need a lot of it to stay in contact with the material long enough for it to work There is no way for you to "check" what it does, so it is probably something that does NOT do anything beneficial but at least doesn't do any harm.
2. Check with the company. But, if it "kills" the buildup in the pipe, it will probably do the same thing to the septic tank.