How is it when on the belt? Some designs tighten up when worn... so it may be too loose in hand but ok on the belt. ?
To best break in a holster you should just use a plastic baggie and time. For really tight ones, 2 layers of plastic. But when you wrap it and wet the leather you will way overstretch it and lose some of the definition that holds the gun in place. It's like a good pair of boots- once you wear them out, they really can't be saved.
And each time you wet it, the leather loses more rigidity and more definition... it may be possible to salvage it for a period of time but it's going to loosen back up pretty quick.
Silver lining: This is black friday, you can redeem yourself for less than normal.
There are some other possibilities, like adding a stitch line, alcohol molding or tensioners but at this point you may be better off licking your wounds and buying a new holster.