i am absolutely positive swallowing or not as no effect on std. as soon as you put the penis in your mouth if one of you is infected there is a risk to transmit. Yet most people that get a virus never actually develop it. Thankfully. Transmission via oral sex is very very low versus unprotected penetration. And that's exactly why data showed us non escort girl or men, have more std. they simply want to please their partner... they think nah it won't happen to me so i can go without a condom.... big mistake.
One important thing, as an escort you should ask all your clients not to brush their teeth for 24 hours before a meet. A toothbrush can create small lesions which will transmit virus so easily. If you are a girl use an electronic toothbrush, they are softer, do not create lesions and will clean your teeth perfectly. If you are a men Just rinse your throat, or like me i buy Vitamine water, its like a gatorade. It gives me a pleasant mouth breath even if i didnt brush my teeth.
HPV is on the rise for all people under 40 right now. Talk to a doctor to get the vaccine. It works. All data i have seen shows it. For men hpv is often undetected and leads to throat cancer. Yet its not like smoking or eating very badly. Don't hesitate to eat as much pussy or penises as you want. It's part of life. Just make sure you get tested often