T.C.
I recently took a waxing class to get some CEU hours.... I was shocked at the volunteers who got their legs, bikini and underarms waxed! I am such a wuss when it comes to just waxing my eyebrows... I volunteered for that only! The girl who did her underarms was wincing before they "ripped" it off. After that she was completely fine with doing it! It was more fear of the unknown! She said it felt the same as doing her eyebrows!
It lasts a couple of weeks before needing to wax again- depending on texture and amount of hair. The more often that you do it then longer in between. Also the longer you do it the softer the hair will be as it grows back in.
As for ingrown hairs... I do not remember exactly what they said in class but something about having less ingrown hairs than you would with shaving!
Good luck to you!