What adhesive to use?
Solvent based silicone adhesives, are best for sticking silicone prosthetics.
Water based acrylic emulsion adhesives, are great for sticking latex, foam latex and gelatine. These include Pros Aide and Telesis Beta Bond. These are cheaper, but cannot be used with silicone that don’t have a plastic barrier.
For more information, please read this article http://www.learnmakeupeffects.com/sticky-situations-the-zen-of-prosthetic-adhesives-removers/.