Use Tectron (not the Chevron stuff, this is made by Blue Magic) a brand of
what we in the outdoor industry call "DWR" (Durable Water Repellant). Any
specialty outdoor store whould have it and it's not terribly expensive.
This is basically a teflon spray, and doesn't leave any residue or
discolor. After application, which is a piece of cake, you can see the
water dropplets bead up and roll off fabrics, leathers, boots and such,
just like water off a ducks back. All Tectron products are the same
formulation so buy the least expensive one you can find.
Later,

Dave & Sherrie
Williamsburg, VA
           zzzzzzzzzz__
         |E[__] [__]|[_]\\
         | _DC&SP | _ ||
* * * =-( )---------( )--=