(I just feel like I'm stalking your posts now
)
There's a few different ways people make squeakers work (physically, though not doing it constantly also makes it more adorable
)
If you just have a dog squeaker in your mouth, I'd just shove that inside your cheek when you want to get a drink. Some suiters who use dog squeakers actually put the squeaker inside their paw, not necessarily -inside- but between the paw and your hand. They then just move their head and act like the sound is coming from their mouth
Another thing as an alternative to dog squeakers are bird whistles.
https://www.youtube.com/watch?v=rC-3un6cmUwFor those though, I'd imagine you just use a straw to drink water and put if far back enough and hope for the best
I use a bird whistle from them and do a 'chatter' for my bat fursuit. They're hard to get used to, but as long as you let the paper dry after each use, you can reuse them. And they stay in easier after they get stuck to your tongue