Here's how I've done it, and it works great everytime:
1. put packing tape over finger and thumb holes
2. put the dishwasher on air dry- YOU DON'T WANT HEAT DRY!
3. put the ball on the bottom rack
4. I don't use any soap. Haven't tried it, but it works great without it.
5. turned on the dishwasher, and let it run it's cycle
6. after it was done, take off the tape, put it finger holes down, and let what little water that got in, run out.
7. take the ball back to the surface you'd like it at
8. take it to the lanes and score! looks great, performs great, what more could you want!?
Nothing Hit's Like A Hammer