Arena Dust Control:

FYI for dust control in your riding arena or hot walkers...Russet stables sent us this valuable morsel about the use of Magnesium Chloride as a means of effective and economical dust control.  It is said to be the preferred product as opposed to Calcium Chloride which has ill effects on horse hooves and your boots as well due to its corrosive nature.  The same is true, although to a lesser extent, for potassium chloride and, of course sodium chloride (salt). 
They go on to say that it can be purchased in 50# bags for a cost of about $12/bag at Fastenal.  It's about $20/bag elsewhere. 
The application rate the first time is 50#'s / 500 sq. ft. This should last about a year with subsequent applications said to be at a lower application rate. 
So if you need to control dust google Magnesium Chloride!
Here is the link for the product on fastenal's web page:
http://www.fastenal.com/web/products.ex?N=999601493
Remember you don't want any Calcium Chloride in the product. Just Magnesium Chloride