Crib halt for railroad ties?

["guest@endurance.net" <guest@endurance.net>]

Kathy Klein Findaklein@aol.com
Help Ridecampers!  We are building our horse area and within where they will live, need to shore up the lunging flat(goes down to sloping hillside) with Railroad ties.  Hence the problem-
I don't think that the product called cribhalt is something I want my horses to even think about chewing on!  If it is toxic to fish, and your skin, seems to me it will be toxic to them also.  So what can I put on the railroad ties to discourage chewing?  I thought of cayenne pepper paste, but it would attract bugs and you have to put it on often.
any ideas or solutions would be greatly appreciated!
Thanks, Kathy Klein