I coach football, but I officiate baseball. No coach will use tobacco on a field where I'm working, period, end of discussion. If he wants to challenge me, he'll find himself in the parking lot. And yes, that has happened.
When I first started umpiring MANY years ago, catcher would turn around and offer me tobacco. Now, if I see that pouch or can, he gets warned to get it out of here.
I'm not doing dugout checks, but if I see it, it gets removed right now, or he does.