Cats hate water. Put him in a bath tub, full of about 3 or 4 inches of water, with the faucet still running.....we had glass shower doors....so we shut them.....and watched from outside....he was jumping all over the place, trying to climb up the walls....jumping straight into the clear glass doors.....bouncing all over the place.....i cried really hard watching that....it was soooo hilarious....
Another thing, if you have a fenced off back yard, put it out in the middle of the yard and chase it around with a garden hose spraying it with water. I swear my cat could run 40 miles an hour when you'd go after him with a hose!!!!
Do you have any swivel rocking chairs? Put your cat on the chair and spin it around about 30 times, fast. Then stop it, pick up the cat, and chuck him about 15 feet. My cat ran into tables, walls, and fell down the steps. And walked crooked.
Hot sauce (the HOT kind). Put a little on their nose.
My dad actually clipped two cats' tails together and hung them over a clothes line when he was a kid. He said they would just beat the crap out of eachother. I'd love to see that.
My dad also tied a brick to one cat he hated and launched it into a pond. That's morbid though. Don't do that. My dad was a naughty child.