Don't ditch those coffee grounds! Make sure you are following the instructions to the letter because drain cleaners are powerful chemicals and they can be harmful. If you plan on trying it yourself make sure you have a bucket ready when you unscrew the pipe, cause it is a nasty smelly job.
We use this in commercial applications such as water fountains, ice machines, etc. This is the current U. When we had our tub surround replaced a couple years ago, the company sent in a plumber first who checked everything out and said that our drain was slow probably because the pipes weren't at enough of an angle.
As you pull the hair up, slice through the middle so you don't need to untangle it. If it is, put the stopper back in the drain.