Can I make an alternate suggestion? Invest in something like the epilady. It pulls hair out by the root. Tell him to shave the hair and when it has grown enough to go into a bathroom (tub preferably) and go to town. It KILLS at first and then you kind of get numb to it. The shorter the hairs the easier and less pain (but not too short). Also every time gets easier and unlike waxing you do not need a "length" to do touch ups. Eventually you not only damage the roots and weaken the hair but also you are only doing touch ups which are barely painful.
I used to do this to my legs and underarms until I got lasered. My ex-bf finally gave in and did it to his chest. IT IS NOT easy they chicken out very fast, the phrase at what price beauty does not apply to men quite yet. If he can tolerate it then he may continue with it. Perhaps getting him a bit drunk would help the first few times!