The best thing I found holster wise to deal with sweat, was kydex. I work physically outdoors year round, and until kydex came along, my gun and I both suffered through leather holsters. Kydex eliminated all that.
I know you said youre a leather type guy, but when you finally get tired of dealing with it, come on over to the plastic side. Once you do, youll wonder why you waited so long.
“The enemy is anybody who's going to get you killed, no matter which side he is on.”
― Joseph Heller, Catch-22