Hi Jenni! I had this exact problem with my OF orginally. No soreness, but
he hair was sheared off on the loins. I tried lots of different solutions.
What finally worked was a sheepskin hide (unshorn) with the fleece side
against the horse. You cut it to the shape of your saddle and its actually
pretty good looking. Like magic, no more loin rubbing :))
Sylvia & Harca -- 5,000 AERC and NATRC miles with the OF and sheepskin combo