I am sorry to say that Steiner is well-known for pushing its beauty product line, and that they would put someone in a position like this through extensive training to do so does not surprise me at all.
However, the way you phrase it, you make it sound like your brother had no idea what he was getting into when he signed up with Steiner, or that they are holding him captive or something. That's Steiner. Just reading our ship reviews or crew message boards would tell you that.
Steiner does include on a pretty "hard sell" as a portion (usually at the end) of every massage, facial or other service they offer, but it is just a part of the job. My guess is that your brother is a little upset about that, but exagerating when he says that is the only thing his job entails.