Iontophoresis treatment advice needed: burns/treating backside of hands

I just started ionto a few weeks ago and so far it’s been going really well, except that the second time I used it I pretty severely burned in between my fingers and my hands were raw and painful for multiple days after. I only had the machine on 11 mA, so I assume it wasn’t an issue with too high of a current. The only advice i’ve been able to find about this is that you should put vaseline on the area, but I would like to still treat in between my fingers so I don’t really want to do that and risk not having the treatment work there. Has anyone else experienced this and found something that worked for them?

Also, my hands have been pretty much dry on the areas that I have treated, but I am still sweating a decent amount on the backs of my hands, which is not too terrible but definitely a strange sensory experience. Would I be able to flip my hands around and treat the backside or is that a bad idea? I’ve read that the skin is more sensitive there so I am a bit wary of trying it. I was thinking that I could try a lower current and do very short sessions (the sweating is very mild on the back, just annoying)