Well my OH uses her toys on me!
We tried bullets and the ears of a rampant rabbit, but the vibrations were not strong enough to make me cum, only just make me erect.
However, The "Tracey Cox Supersex 7 Function Wonder Wand Power Vibrator" is amazing, and I imagine other wands would be just as good. We used the wand in a rubbing motion, on the frenulum (bottom side of the head) and it gets me erect within seconds and within 2 minutes I cum hard.
So my reccomendation is if you want a toy to make your fella cum, get a wand!
Horny Young couple!