I tried applying some neutral cream to the soles, as some websites suggest to ‘nourish’ the leather, but it made it more slippy on hard floors. Some suggest using neutral polish but I’m certainly not doing that as I don’t want to take a tumble! I might just leave it dry but some say dry leather soles soaks up wet and shortens its life?
There is really no definitive answer to this question.
The Saphir sole oil does work to repel water, though. It quite obviously beads water, rather than soaks it in; however, I am not sure that is in any sense a positive thing or not.