Exactly. It doesn't sound like many realize the amount of water that sits in that hole as its being drilled. Yes some is expelled which can be vacuumed up but when the the bit is through there will be a bunch of dirty water all over whatever's underneath. If it's a smaller hole (<1.5") and a small slab (<12") my choice would be to do it dry, especially if the floor is say an 8-10" poured coredeck. The drill can handle it, it won't explode from lack of water. Ive done a whole office buildings worth of poke through boxes this way without a single issue.