Molten (Props and Online Instructions) by Morgan Strebler - Trick

Borrow a glass bottle from a spectator and pour out any remaining liquid. Then, without any unnatural movement, begin to alter the physical properties of the bottle by simply rubbing it with both hands. As you complete the dramatic transformation of the bottle, the audience realizes it is now permanently distorted.

There are VERY few effects, if any, I've performed over the past decade that have garnered stronger reactions than Liquid Metal. However, MOLTEN has generated the most outrageous spectator responses I've ever witnessed. I believe the audience perceives MOLTEN to be so "impossible", so "clean" that the only possible, rational explanation is, "It has to be real magic!" By far, this is my favorite offering released to the magic community.