You can always place the mouthpiece in the saucepan, then run cool water over it. Just remove the mouthpiece from the pan before you heat the water.
The mouthpiece will be very hot when you take it out of the boiling water, and you don’t want to accidentally burn your mouth.
If you’re using a spoon, use a slotted spoon for best results. The holes will make it easier to remove the mouthpiece without collecting water.
Don’t leave the saucepan unattended while it’s on the stove.
Don’t heat the water for longer to 90 seconds, or it might ruin the mouthpiece. [8] X Research source
Don’t hover your face over the steam, as it may burn your skin.
After you remove the mouthpiece from the water, it’s a good idea to touch it carefully with your finger to make sure it’s not too hot to put it in your mouth. If it is, you can dip the mouthpiece a second time.
The mouthpiece will be soft and pliable, so don’t bite down on it several times. Each time you bite down, your teeth will leave an imprint in the mouthpiece. It’s best to bite down just once.
If your mouth feels uncomfortable, try to adjust your bite so it feels better. If the mouthpiece isn’t soft anymore, boil it a second time so you can try again.
Don’t shift your teeth or release your bite as you do this. Biting down on the mouthpiece is most important for shaping it.
If it doesn’t fit, you can start the process over and try again.
