Hold the pipe behind your teeth to prevent this problem (credit to the OP of the hints & tips for meth smokers)
It will still cause damage and the OP still needs to brush his teeth, either way. The chemicals in meth are so strong that just having them in your mouth causes damage. But yes, definitely make sure the pipe is behind your teeth it does help.
Plugging is the least damaging ROA that rivals IV in the euphoric rush (but of course isn't nearly as good, rush wise, but with a longer overall high), but is still better than snorting for most people and has really high bio-availability and little to no burn/irritation, unlike when snorted. But since you'll be with friends I doubt you wanna be running to the washroom with ur oral syringes stashed away every time u wanna dose lol they'd think u were shooting up or something, unless they'd be cool with plugging but it's not something i'd bring up to any friends lol.
Other than that you got oral ROA which apparently is actually a much nicer, full experience with less of a comedown and a longer duration of the overall high, but of course minus as much of an initial rush and a longer wait until you feel full effects (depending on stomach contents, 15-75 minutes).
And of course smoking, but I've heard that is all rush and generally is an overall much shorter high with a harsh comedown, and a lot of people report they feel sketchy pretty early in a binge when they are smoking their shit.
So from a hard reduction point of few, either oral or plugging (rectal).
But you'll likely snort it anyways, which as long as you don't use meth often should be fine.
No offense, I appreciate that you are trying to contribute HR information which I 100% support, but I can tell you don't really have experience with crystal.
Very few people are going to plug their meth. Initially, meth is a very social drug. No one is going to plug anything around other people lol. And some goes with oral.. you swallow it and it's done, that takes the social part out of doing meth. And since it's meth, unless you're IVing, all the methods are just as damaging. Except for snorting, which I'll go over below.
Most people smoke or snort with friends. Later on, when people get hooked and really strung out and fucked up, they'll do it alone and may move on to IV. Though you would be surprised how many people just stick to smoking.
Snorting, like I said above, is just extremely damaging to your nose. There's no rush or euphoria and the high is much more edgy and most people I know, including myself, got much more anxiety and a worse come down from this method. But it's easy to do since you don't need a pipe or foil and if you're trying to do it in a bathroom or something once you're out it's easier to do without getting caught.
In this situation, I definitely suggest smoking. The OP is doing it with their friends so passing a pipe around is fun and social. Providing you use mouth wash or brush your teeth it's not as damaging providing you
smoke correctly. Don't let the pipe touch your teeth and definitely smoke with the pipe far back in your mouth. Keep the lighter as far below the pipe as possible so you don't burn it, wait to inhale till the meth is fully melted, and exhaul immediately when you're done smoking it. Holding it doesn't do anything other than cause more damage. It will NOT crystallize in your lungs, that's just a myth. Meth is fully soluble in water and will absorb in your body since humans are 80% water.
90% of the people I've met who use meth smoke it. It has the most euphoria, you get the rush in the beginning, and it's the easiest way to use it since it doesn't taste bad or burn your nose. You also get a lot of pleasure out of smoking.. you definitely get a body high that feels amazing. And the comedown is relaxing in comparison to comedowns from other RoAs! I shudder just remembering the comedown I had last summer when I snorted a bunch of crystal

That's the last time I used too.. and it had been the first time in 6 months. It's not my thing anymore.
OP, if you smoke before you go out brush your teeth for a full 5 min afterwards. If you smoke once you're out, bring mouth wash and use religiously. I listed above what to take. Protein will definitely help as well, but as long as you eating before, during, and after you will be fine. And take vitamins to help prevent damage and speed recovery.