Subs, T's and the Real world

[Chess Ref]

Okay I can see that I might be looking for boogers here but it is bothering me. Kids jumping up from the bench and not checking in. This is HS BB, by now they should know how to check in.

I have sent them back to the table, I have talked to the coach about it and then I have the kids giving me the bum's rush from the bench.

My question is would I be venturing in stepping on it land if I Gave a T as prescribed in the rules ?

And if so have many of you have actually done it this year ?