the only thing that had any real effect that i have tried was yohimbine HCL take it a couple of hours before. also zinc helps. (remember oysters, its the zinc).
i once had this bad ass cold and bronchial problem and was givin this bottle of stuff for it, it didnt have a hardening effect, but made for the most explosive orgasms in my life, wish i didnt throw that damn empty bottle away.
for women:
Damiana Herb, and a couple of aminos L-Histimine, and L-Arginine. yohimbine, (small dose) gurana.
the L-arginine and yohimbine help deliver blood flow to female genitals, Damiana helps put her in the mood, and L-histamine helps with the orgasm.
L-histamine should help men with more explosive orgasms also.
have fun