Nuru & frottage are similar, but not exactly the same. Frottage is simply rubbing dicks, where as a Nuru style massage involves the entire body. As for what they're doing with their faces, in my experiences with Nuru massages, it's always been kissing. It's kinda weird to just stare into someone's face while they're oiled up and grinding against you.
I say go for it, and if you need a Nuru provider here in NYC, I can recommend one.