The upstairs shower drain has been a long term issue that has gradually gotten worse. We had a plumber work on it with minimal success. So I went to HomeDepot and bought a drain snake.

The crank pops off and a regular drill can be attached. You have to be careful to keep the drill aligned with the drum to avoid putting stress on the shaft. The drill works great, much, much, better than cracking by hand. Go through the overflow drain to avoid sharp turns. Worked great! Problem solved. Should have tried this before going with the plumber.