I'm the guy that turned Tony on to Mark Lee's products and I've done quite a few damascus barrels....they always come out really nice with a good pattern when carding by hand with steel wool....
No, do not dilute the mixture...works fine out of the bottle....
I use an open glass jar with the brown in it and dip pure cotton shotgun cleaning patches as wipes, new ones each coating of course, wiping the brown onto the barrels while the barrels are held vertical over a plastic plate while still warm....again, wear rubber gloves....
Heat the barrels with a hair dryer or commercial dryer between each coat before applying the browning....
