last couple of wedgies I've done I used plastic "shrink tubing", I bought a kit of different sizes and lengths off of ebay, got a bunch in it, costs about nothing. This will insure no juice coming down those long thin rods that the steel buttons touch conducting.
By the way , the door is also hot and will give you a real jolt, I mean a REAL jolt! "thought i was gonna die" type jolt.
But of course thats just me, I grabbed a plug wire on a G Production Datsun "Fairlady " once, that was worse but still, old Gottleibs will clear up that stuffy nose for sure.
Don't forget the coil sleeves on the flipper coils.
If you have done all the stuff mentioned here by all these good people and still need some more power, The Pinball Resource sells "yellow dot" coils that I have had great results with.