No, I don't think it will strip the paint off, unless there is rust. My tank didn't so much as fade in the electrolysis, and was still glossy when it came out.
Although, I did notice that the rust doesn't all literally fall off, a lot of it ha to be wiper off, or wire brushed.
My anode was too small for what I was trying to do, so I need to re-asses it before doing any more. I might go weld up a bigger anode out of some steel scraps laying around.