well you could get the innards of a crybaby and put them in the casing of an ernie ball volume pedal like kirk hammet did
^For a kick?
"Breathe, breathe in the air
Don't be afraid to care"

Fender Strat/Tokai LS80>few pedals>Orange Rocker 30
Slash used an Ernie Ball expression/volume pedal to control his rackmount wah. The Dunlop rack wah can be used with a separate expression pedal - not necessarily Dunlop's.

Hope that helps.
Epiphone Les Paul Standard Plus '02
Fender Highway One Stratocaster
Roland Jazz Chorus 120
Marshall 5210 Combo Amp
Fender Silverface Champ