I used to have frequent problems with hair clogs in the tub. We used everything, even the very "best" (really, worst :
) professional stuff at Home Depot. Then one day I tried boiling water, baking soda and vinegar and it is AMAZING!!!
I pulled out all the hair I could, poured a kettle full of boiling water in the drain, poured about 1/2-1 cup of baking soda in the drain and kept adding vinegar little by little until I could not hear the bubbling anymore (at first it will bubble at the top, then it will move down the drain). The first time I followed that with a few plunges and another kettle of boiling water.
We used to have a plugged drain every 2-3 months but not anymore. Now I just pull the hair out when it starts to slow down and that is usually all I need to do.
Also, there are LOTS of NASTY chemicals in Nair. Try the baking soda and vinegar before you go that route.