My solution to this problem has been to make my own leather nuts.
Go to a tack & saddle shop and get the vegetable tanned thick cow hide
scraps.  The acid tanned leather, of which the leather nuts are made,
will irritate a horse's skin so it is not used.  Because of the oily
nature of this kind of leather, the nuts seem to go on much easier.

Brian Thornton - Short Mountain Music Works
Woodbury, Tennessee
http://www.shortmountainmusic.com/