Very Serious
I can't take it seriously
Have you seen those youtube video tutorials on how to please genitals? They use rubber duplicates, maybe you can do that. Best to do these kind of sex work if you're actually talented in pleasing others though.
However, if you actually WANT to finger someone's prostate or whatever, maybe study in proctology. They study the colon, rectum and anus. I must warn you that you won't always be fingering hot men. You'll be shoving those gloved fingers of yours up a grandpa's ass, asking them to cough or whatever.
I wanna apply for a job similar to Miss Aya's. How do I get her job to the point where I teach people how to finger?