i did a MOSFET for MORANS thing here .
http://candlepowerforums.com/vb/showthread.php?t=84242
complete with purdy pictures, so i could understand it.
some of the mods that use a 2pos switch have used a .5amp switch to run 1Amp through it, if your switch is good for a FULL 6amps, it might work up to 12 before it melts and smokes
just depends on what the VOLTAGE that switch is rated for also.
because when you try and disconnect/connect high voltages they have a tendancy to arc and make an arc welder and all. if it was lower voltage than spec you might get by with a lesser switch. like say a 6Amp 120VAC switch might work easy to 10amps with 12v dc.
and should i mention that an added electrolytic cap of the right voltage, will stop any OFF arcing too, adding life to the switch component, without taking much space or efforts. like they used to do with "points" on a car. (which also had backlash from the coil) the energy that would snap between the switch, will insted charge the capacitor.