Tim,
I have this problem as well, just from regular wearing. The back of my socket rubs through my jeans and will wear through.
You said you tried a leather patch, but it looks dorky. Have you tried putting it on the inside of the jeans? I am going to sew in some patches on my jeans and will put them on the inside. I have even considered putting a patch into brand new pants, on the inside - as I can predict where they will rub through.
If the holes are only occuring from your riding, could you wear a set of chaps? Eventually the chaps will wear, but it shouldn't be as quickly.
Is there a specific part on your socket that is causing the rub? Could your prosthetist pad that part?
Ann
RAK amputee, Michigan
Western/Trail riding
Spotted Draft Horses