Tongue piercings are one of the most septic-prone piercings out there; even more than belly buttons. I knew one woman whose tongue piercing got so infected the swelling started to close around the piercing; but to remove the stud would have mneant the flesh woudl seal in the infection and make it worse; she suffered for weeks...our mouths are NOT clean places and that is why lip and tongue piercings are kind of nasty...
Ironically enough, genital piercings are far les prone to infections; urination is one reason they are what is called "self-cleansing" (this is a piercing term), as opposed to other areas where one must clean the piercing repeatedly to prevent infection.
I was engaged to a guy with several genital piercings. He later got a tongue piercing.
(shrug) Nothing special about it either way. There's metal where there wasn't any before. But no new super-powers. I think he thought the added attention might get him more sexual attention; perhaps it did. But I don't think piercings in and of themselves enhance sexual performance or pleasure.
Not in my experience anyway. Though I do like nipple piercings on men.