If you have a shop vac (Wet/Dry vacuum), this is often the most effective non-chemical method.
You might be surprised how often the clog isn't deep in the pipes, but tangled right at the drain opening. clogged bath
You drop the mass into the trash can. It lands with a wet, final thwump . You pour a kettle of boiling water down the drain, then a cascade of baking soda and vinegar that fizzes like a vengeful science fair project. Finally, you turn the tap. If you have a shop vac (Wet/Dry vacuum),