Quote Originally Posted by Utopian View Post

It has nothing to do with any change in the drag or resistance of the water during the honing. It only ensures that the hones is uniformly wet over its entire surface.
This is not in disagreement with what I am thinking.

I am not thinking about the drag of the water while honing but the drag of the stone against the steel.

The water with its surface tension will hold the steel away from the hone. Therefore creating less friction between the hone and the blade.

The addition of soap to the mixture will lessen the surface tension of the water and allow the steel to contact the surface of the hone to create more drag/abrasion of the steel.