Not sure about treatments, but I've had lots of experience with combat boots being submerged in saltwater for long periods of time. The boots were standard G.I. black boots that were around since the 60s. When they would dry, the salt would come to the top of the boot and crackle. It looked like the salt and water were merely messing up the last coating of kiwi and not really affecting the leather. We would just clean them with warm water and a soft bristle brush and re-apply a sturdy coat of black kiwi polish. They actually held up great with very little care and I still wear them sometimes with no issues. I think you'll find less is more, let the pores breathe and the leather should somewhat care for itself.