Exactly what part is rubbing and causing the rash? I'm assuming its part of the holster, and that the side in the picture is what is against the skin. If so, the problem is the design of the holster. It should have been made and formed so that side is curved to fit your body and NOT curved around the firearm. It should have laminations on this side of the holster that allows the holster to fit the firearm properly while keeping the skin side flat (curved) to match your hip. I'm not sure that holster can be made to be comfortable as an IWB rig.
I use rigs from Proteq Custom Gear. They are comfortable enough that I can lay down and take a nap and not realize I still have it on when I wake up. They are expensive, but they are worth every penny.
I use rigs from Proteq Custom Gear. They are comfortable enough that I can lay down and take a nap and not realize I still have it on when I wake up. They are expensive, but they are worth every penny.