Hi Amy,
I too use to have girth chafing problems. One solution I found to work great
on my mare with chafing behind elbows, was to bring tie strap down though
girth ring, bring up into back cinch ring back to middle of both straps and tie
also helps to hold back of saddle in place better. I ride an Aussie saddle, and
I can use any type of cinch (cotton string, neoprene, or a fleece) without
problems anymore, also the fabric softner may be the cause also, it might be an
irritant to your horse. Hopes this helps!
Chris and Ginger