Drain uncloggers are a caustic. Meaning they are a strong base that eats stuff away. They are generally safe to use except for two very specific circumstances. you really don’t want to use them if you’re on a septic system. It will kill the good bacteria that eats your poop. It’s not a deal breaker, your system will repopulate eventually. But it could lead to a backup. In my opinion - just don’t use that stuff with septic tanks ever. if your pipes are old af and on their last legs. Or some of your joints are shoddy. Draino might eat through that last little bit of metal and cause a leak. But to be fair, a snake could bust something open too. This isn’t a problem with modern plumbing. Nothing you can do about it except watch for leaks no matter what you do (or replace that old plumbing). I’ll offer some advice. For like $35 bucks you can buy a real honest to goodness plumbing snake that’s hand operated. Mine has a little orange saucer thingy the snake coils up into. You pull out some of the snake, and stick it in the drain. You push with one hand, and you use the other to twist the snake via the big hand crank knob thingy. You push a foot or so of the snake down the drain, then pull out a bit more of the snake from the saucer, and then push that bit down the drain (always hand crank spinning). It’s SUPER easy to do. The one I have is like 25 feet long, and I have cleared some of the nastiest clogs with that thing. I’m talking 5 foot long clogs of my wife’s hair/grease/soap grossness. Draino would never clear that - but the snake makes short work of it in less than 10 minutes. I spend a few bucks on some rubber gloves instead of hundreds on plumbers and expensive Draino. TLDR: get a hand snake. They work amazing, are super easy to use, and are less money than Draino (and plumbers)