how about this??
charge every one coming in an extra 200 bucks on their credit card regardless of what they are using,wheel house,shack,shanty,flip over what ever,give them an ID number with the understanding their area will be checked when they leave and video taped.
if there is ANY trash what so ever left when they leave,they dont get a refund period.
those that have a urinating contest over it are probably your violators to begin with and they can just turn around and go some where else,if they can afford some of the equipment you see being towed around these days,a couple of hundred bucks wont turn them around.
sure,its going to require a bit more man power to cover this and you may lose a bit of business, but I wonder if its cheaper in the long run versus what it costs to get rid of the tonnage of trash left over.
ya,I know,there I go thinking again.