Although I don't approve of drowning, sometimes people have no other option.
The drowning discussion pops up everytime it is mentioned and almost always ends in an argument or a mod stepping in. So, let's just drop it.
The logic behind using urine is that the testosterone is what drives the animals away. So male urine would be higher levels of testosterone and would be easier to "dispense" fresh into the yard.
So maybe have some male guests over and offer them plenty of water and other liquids, then point...