Re: the mosaic thing with tobacco, I tried tobacco once and it was like an acidic vile solution that would make a dead mans toes curl up. Not recommended, But TMV as I understood it is a virus that attacks tobacco plants not one that is caused by processed tobacco leaves being brewed up. All you smokers and chewers don't need worry though because your beautifully blended tobacco leaves have been subjected to so many chemical processes that even Cher's face wouldn't survive. if a fungus strain can survive that then they need to be expelled from planet earth.
Tomatoe leaves contain small amounts of poison, enough to piss them off but I wasn't impressed (my mother in law is alive and kicking).
You could also use urine but then you might attract unwanted mammals like cats, bears and queer folk.
Vinegar pisses them off too.
My theory is that you don't want to kill them outright but leave a few over to tell their friends that the guy with the squirty bottle sucks and that they are sure they saw him piss in it and maybe we should f@$koff to the next door neighbour who has some nice basil plants. Rumours spread quicker than any infestation.
If they come back for dessert than at least you warned them.. No bad Kama here.