Those are all neat ideas how bout this one.
First of all get a piar of locking pasict panties (i chose to call them panties).
Take a water pill and a laxative or a suppository (optional) drink a large glass of water. then go to a mall, try to pick one that is a ways away from your home, maybe a 30 minute drive or better. (be sure to leave the key to the lock at home)
When you get to the mall stop by the food court and get something to drink with the biggest drink the shop has to offer.
Now make sure you planned an odd route to go so you go to a lot of shops but in an order so you cross areas of the mall multiple times. (Go from one store at one end to a store at the opposite end, etc.)
Be sure to go to at least 10 store and spend atleast 5-10 minutes per store.
Anytime you walk by a hall or area that has a water fountain, stop for a drink.
When you feel like you are bursting to pee go to one more store for a few mins then leave and go home.
If by some FREAK chance you make it home, not only are you going to be in a bit of pain from having to pee but you have incredable control. Hopefully you dont do any damage to your body in the process.
If you havent gone by this time get a big glass of water and drink it while letting the water run.
Hope you diaper holds at this point