I’m tempted to come up with some bizarre and fictional masturbation technique to share with you so you can try it and report back.
Instead, I’ll ask if you’ve tried electro-stimulation at all. Nothing revolting like wiring yourself into the mains or doing the Ben Franklin thing, but just springs and wires and batteries, attached to the good bits. Gentle tingles that can be pulsed on and off in your own preferred sequence.
On an unrelated note, a lot of people were shocked to discover that my Uncle Frank was not actually a licensed electrician.