If it's too painful, scale back to 18V and throw salt into your water bath to increase the conductivity. I used 24V and started getting small blisters.
Electricity chooses the path of least resistance!
Put vasoline or Aquephor on your nails and cuticles and then get your hands or feet in the water bath. That will eliminate the sting
The vasoline will be a barrier for the current and very little or no electricity will go to the parts that have vasoline or Aquephor on it. The parts of skin that are exposed, will be the site where the current will flow and subsequently bring the hyperhidrosis under control.