I keep regular mouthpieces on the bench for servicing regs because of this. Nothing worse for me than to get a reg in with one of those long bite Sea Cures in. I won't even test breathe it with that on there.
No shop should have any issue at all with you getting him something like a comfo bite and swapping it on the regs.
It takes less than 2 minutes to do and the only cost is a zip tie. If they won't do that, swap it yourself and tell them to deal with it.
In today's environment it's better anyway from a health and safety standpoint if you are not 100% they are sanitizing their regs for every class.
No shop should have any issue at all with you getting him something like a comfo bite and swapping it on the regs.
It takes less than 2 minutes to do and the only cost is a zip tie. If they won't do that, swap it yourself and tell them to deal with it.
In today's environment it's better anyway from a health and safety standpoint if you are not 100% they are sanitizing their regs for every class.