Use of a suppressor is a fish and game violation in Vermont. I thought the fine was $50, but I maybe wrong.
As previously said, NFA Branch would not approve a suppressor transfer to a VT resident, but no dot 20 is required either. An out of stater could bring one in, and if used discreetly, who would ever know or really care. Get caught with one, I'm pretty sure it will be confiscated and BATFE would be notified to give you at-best a hard time.
I think the suppressor law comes from a real concern of poachers. There's already enough going on - that and road hunting.
There is some sentiment in Southern VT, which has seen an influx of flatlanders post-9.11 for recreational use of a 22LR suppressor. Call it a "good neighbor" policy.
VT is sooo gun friendly, it seems at odds that about the only thing they don't allow is suppressors. Until you hear that shot in the dark.
"Yeah, that's easy for you to say, you're Mr. White, you have a cool sounding name. Alright look, if it's no big deal to be Mr. Pink, you wanna trade?"