[SiVal]

Yes, see my comment elsewhere on this page. I've done it more than once, and it always worked like a charm. Desperate people will try to get on top of you if you are floating; they'll drop you if you are dragging them under. I've always been larger than the people panicking, so I can't be sure a small person could drag a larger person under, but if your head is already under, trying to go deeper is your only viable option. If you try to come up, you'll have to lift them, and they'll stay on top of you.