"Don't put liquid chlorine in with the pucks"

I have a floater, so if the pucks go anywhere, it's in the floater.
If I put liq. chlorine in the pool. I pour it in at the deepest part of the pool slowly with the pool pump on for at least an hour, same with muratic acid.

I guess I don't understand how you could put liq. chlorine in with the pucks? Is this with an in line puck holder?