Only a bit of wisdom here...but I would guess the revolutionary fellows did the same thing....one need only hide their weapons to set the engaged police dimwit back into position. No policeman can enter a house without a warrant. If you don’t invite the guy in...he can’t enter. I doubt if many judges will find logical reasons to hand out search warrants left and right. And to make the cops feel a bit of a dope...I’d have water pistols out and offer them to the dimwit. Of course, I’d have a guy with a camera just around the corner taking picture of the confiscation of my water gun. Looks real good on the internet and TV...and makes fools of the police...which in this case...they richly deserve.
That might hold if you are every rich in a upscale neighborhood ($2 mill plus houses) but for most of us, I think just innocuously opening the door will be cause enough for him/her to see something suspicious enough to force their way in if that is their intent.
And then if you resist that entry, now you just might be one of those people barricaded in their own house and you will be rescued ala the Janet Reno method.