At one drowning every 12 days that sure must have cut into your lawn maintenance time. I'm curious where you did the deed, how far you transported your victims, in what sort of cage-vehicle combo, and how you disposed of their corpses?I have had the same problem for years and I have tried everything listed above and more. Here is what works for me.
Grubs are a key factor and I go to the US and get grub killer to spray on the lawn.
That only solves part of the problem because the racoons are still filthy, potentially rabid and will do lots of damage in addition to the lawn.'
Next is the live trap. I find peanut butter works best. But don't transfer your racoon problem to another neighbourhood. I drown them. I believe it is illegal to transport trapped wildlife more than 1.5km from where you capture them and that's just a night's stroll for a racoon. You have to finish them off and I concluded a drowning was the quickest and surest way. Racoons are out of control.. In a 12 month period, in an urban area of the GTA I trapped 30 racoons on my property which is 110 x 45 feet.
Just imagining the mechanics of getting a dead raccoon out of the cage you drowned it in, never mind how you might drown an uncaged one is enough to make me dubious about truth and civic responsibility levels in your story.