Experienced soap stampers: do you have any tips for a really clean stamp? Do you rub your stamp with anything? How long do you let the soap after unmolding before stamping? Do certain recipes give an easier stamp? Do you press the stamp in to the soap or use a mallet? My stamp is locally made but similar to the Laser cutz stamp. It's new, and I seem to get 1 good one and 3 messy.