I just tried regular old water in a mist spray on the leather strops last night and oddly… it doesn’t seem to work anywhere near as well as alcohol. It does have a bit more grab to it but not the super amount of grab Geocyclist describes above. It doesn’t seem nearly as effective and may even have lifted some of the paste out of the leather… at least the black spots now have brown showing through after using water!
It seems like the unique properties of rubbing alcohol require further study 🙂