OK that's interesting, haven't asked for bareback so can't comment, but pretty sure would have got a 'no' from general comments the privates I've seen made regarding how important it is to have safe sex and all that.
My assumption on STI risk was more around:
- sheer volume of customers shop girls see and unprotected oral etc., so statistically speaking - x% risk per encounter multiplied by no. customers
- also, my understanding via online forums that bareback is quite rampant in the major shops (smaller ones too), particularly with Japanese WLs, and especially the FIFO variety