will a headphone splitter allow me to use 2 kick pedals with guitar hero drums?

i have ordered guitar hero metallica and i want to get a second kick pedal. there are things on ebay charging $14 for this metallica splitter but if its just a basic headphone splitter which i already own then i dont need to be ripped off paying $14 for a splitter thats worth about $1

anyone know what the deal is to get a second kick pedal working?

i think you could use a headphone splitter as long as the bass pedal is cable 6mm