- Vagina substitutes. Vagina substitutes come in all special paperwork, however Alpha Core Enhance RX they may be usually a hollowed out tube of a few sort which has been coated with a gentle material. An erect penis thrusts inside and outside of the tube, generally resulting in ejaculation. If the toy is thoroughly cleaned after each use, there's little chance of a rash - however if no longer, a penis rash is pretty likely.