Contrary to popular opinion, vaporeon is not the most breedable Pokémon, it is jolteon, and this is due to basic physics. An electrical current traveling in a linear direction (i.e. clapping jolteon's cheeks) generates a circular magnetic field around the shaft, producing unbeatable stimulation during the sexual act.

While also possible with a zebstrika, jolteon has the advantage of also having much smaller vaporeon-sized holes.