I dunno bro, if the lady has received a CIM from an STD carrying customer, and not disinfected her mouth properly afterwards, and the next customer gets a BBBJ, and he has a cut or abrasion on his cock, i'd suggest there would be a risk of transmission there as well.

In terms of MLs, i take your point these ladies have nowhere near the mileage of WLs. However, they are also exposed to a lot more cum than most WLs (they clean it up, get it on hands, sometimes on body...). A simple cut on a hand that is covered in semen might be enough for these poor girls to catch an STD. MLs often seem less educated about STDs and safe sex practices as well.