Sounds simple enough and they do that very often on the west bank and it seems to work, but how do you plan on setting up such a trap inside of Gaza without entering it with troops and therefore inevitably engaging Hamas and catching civilians in crossfire?
And about the 35 thousand dead, well that number comes from the health ministry of Gaza which happens to be directly controlled by Hamas, and the group has lied about that quite shamelessly before (remember the missile on the hospital case from a few months ago), my point being that not only are the not a reliable source but they also have every incentive to jack the numbers up as hard as they can. Now I have no proof that it's fake but we have no way of checking.