The drain in the kitchen sink is slow. Slow enough the dishwasher backs up into the sink. My baby 1/4" x 10 foot snake found nothing interesting. Boiling water has succeeded so far only in melting the thin Chinese PVC attached to a P trap. Drain-O, it does nothing.
I guess I should be glad it's been three years since the last time I had a snake down this drain, and two years since I replaced smashed-broken pipes. The last time I was in there, I said I would make a more-conveniently located clean-out fitting if I ever had to open the wall again so I wouldn't have to open the wall again. Guess what time it is. Must. Resist. Urge. To. Use. Compressed. Air!
Always buy new PVC glue. You don't want to do this twice because you went with old glue from two years ago.