Confirming P Lead wiring to Mag Toggle

I'm using separate toggle switches for my two Slick mags. The switch being used is a Honeywell Locking Toggle, model 2TL1-3D, DPDT, On-On. What I'm somewhat unclear on is where the P Lead gets attached. If the down position is off and up position is on, which one of these gets the P lead connection from the mag? In other words does the mag need the ground in the on position to run or does having the ground attached to the off position kill the power to the mag? Thanks...

The mag is "HOT" when the "P" lead is open, i.e. switch "OFF". Turn the switch on to ground and "kill" the mag.

Typically a SPST switch is installed upside-down so that the mag is "HOT" with the switch in the up position.