+1 on the Smith's Honing Solution
I found it a few years back and haven't switched since, not only it works well but you do NOT have to worry about cross-contamination with your expensive water stones
It is pretty darn cheap too
you can often find it at a local hardware store,, be careful as they also make actual Honing "Oil" to that is not water soluble
Smith's HON1-4OZ Honing Solution, 4-Ounce - - Amazon.com
Cheaper yet, some people swear by using Diesel or Kerosene but I wouldn't let it in my house or near my Waterstones after hehehe