You spray 4 times a day? How humid is that tank?

I would soak him in luke warm water to loosen up the skin then I would take a wet cotton swab to that roll of skin and see if you can get it to come off. If it is still difficult and isn't budging or if he is getting too stressed, let him clam down and try again later. It may help you out alot if you have someone holding him while you swab or vice versa.

Severa