Yea, that's a good one, but I got some way better stuff, if you have time for a laugh....
Place your fingers inside of a drawer then just before you lift a record attempt slam the drawer with your fingers still inside. This technique spikes a vascular adrenalin rush.
Have your training partner hold a knife to your throat and promise to slit your throat if you don't make the lift. Now you really have to have a good partner here no wimps or anything. He has to be good for his word. This technique appeals to the amigdala, a part of the brain where fear rules.
This is my favorite. Drag your bench and weights down to a motorcycle bar and set it up in the parking lot. When the biggest baddest cycle gang gathers around to see what's going on tell them that if you don't make this one particular lift you will be their bitch for the night.
Have your training partner stand behind you and drop hot candle wax in your face while you are in the middle of the rep. I don't know why this works so well but it really really does....would I like to you?
I have plenty of other tricks that work as well as that ice idea, but I don't have the time to post em right now. I have to get going, I'm working out under a jacked up car tonight and the mechanic has just put the car on some shaky blocks for me.
See you later....IF I am successful with the lift.