More rudder and more aileron make the snap faster, with rudder making the snap more stalled and producing a larger cone. More elevator slows the snap, in my experience, and makes the snap more violent, with the plane's CG moving around more.

My snap mode has lots of rudder and aileron (more than I use at any other time), with medium elevator (more than normal flight but less than a spin). My control input is usually to slam elevator and rudder, then slam aileron and take out almost all of the elevator.

I'm sure there are other ideas on snap throws and technique, so try them all.