I have recently stripped the paint off 2 motors and repainted them, the first one I did was a blue LA46, the second was a blue LA25, I mostly just soaked them in acetone all day while I was at work, I'm a painter so obviously I have access to a wide range of chemicals, acetone was the most effective.
you won't be able to completely strip the paint off even if you soak it for days, your best bet is to soak it a few hours, and then using a wire brush and scotchbrite just go to work scrubbing the crud out of it, use the brush for the cooling fins, you will still have paint in spots unless you bead blast or or whatever was mentioned before, tho I heard years back never to use any type of blasting on a glow engine because it can somehow weaken the case and misshape it, I would just re paint it if I was you, get some hi temp paint and go for it.
hope this helps.


First motor is the 25 the second is the 46