Just my .02, but i smoked a bit with a lip labret and it got a pretty nasty infection. Though I can't draw connections for certain, as I have no other oral piercings and I apparently threw in an incorrectly sized ring soon after it was pierced.
I got my snakebite and smoked right away, but I rinsed my mouth out with mouthwash after EVERY time I smoked/ate/drank for the first few weeks. I didn't have any issues, but if you can manage to wait a few weeks, that'd be wisest.
I didn't have any issues smoking after I got it, but I've never had trouble with any of my piercings getting even slightly infected. I've actually never had a wound get infected either, so I think its just because I'm a really good healer. *shrug* I used a 50/50 for the first two weeks, smoked right after I got my lip and tongue done. My thought is oral piercings get infected from smoking is because my mouth gets dry when I smoke, and I know a lot of people that say the same thing. So maybe that's why.
Either way though, just take care of it to the letter, and if you are smoking and it starts to feel like it might get infected, stop and baby the fuck out of it.
i think it depends on the person and the piercing is the piercing is going to come in like straight conact with it and get easily affected id say wait but if its not then washing it out afterwords would be perfectly fine too im sure.