I admit I recently used this trusty stuff in my clogged condo kitchen sink.
Instant Power from Home Depot
67.6 oz. Hair and Grease Drain Cleaner
https://www.homedepot.com/p/100169339
Someone had repeatedly dumped coffee grounds and pure grease down the drain from other units above me or near me.
When I plunged, they kept coming up in my sink.
We cannot have a waste disposal in this building.
I did not want to wait for Association to eventually send a snaker out, and also all the building’s drains had just been professionally snaked very recently.
My back was killing me, not up for doing my own snaking.
And clogs tend to be pretty far away here anyway.
I was also afraid they would try to blame the clogs on me.
This stuff worked great. My full double sink was draining only about a few ounces every ten minutes. So I did not use any water there all day, and both sinks finally emptied.
Then after midnight dumped in a quart of this, and a gallon of very hot water from the bathtub faucet.
Half hour later I heard gurgling in the sinks, so I ran about five mins of straight hot water, totally cleared up!
No probs since, has been at least three months.