You do *NOT* want to put your iopener is water. This will quite possibly ruin the materials inside. Also, you never want to dry heat it. I had a co-worker borrow mine and he heated it up beyond the recommended time and without a damp paper towel. It smelled like a cheap microwaveable burrito being burnt, or that nasty smell of burnt popcorn in a small office space.
If you follow the proper instructions, it will work. You will have to reheat it a few times and be gentle, but I've used it many times when dealing with iPads that have LCD issues where the digitizer is still in great shape. This tool has saved me countless amounts of dollars and headaches by enabling me to remove the digitizers and keep them in perfect working shape to reuse on the same device after the repair. Customers will be very happy that you saved them money by not breaking their digitizers during removal.