For electric, I just use an air compressor and as little WD40 as possible. I just spray a little on a brush and apply sparingly.

Same with nitro, except that about every month or so, depending on use, I do a complete tear down and soak stuff in simple green.

If you overdue it with WD40 or any pentrating oil you'll start to have problems with screws not staying tight.

Hinge pins, bushings, external moving parts dont really need 'lube'. They work better longer if they stay dry.