Here is what is left of the sling that my new one is replacing (for photos of it when it was new see
http://slinging.org/forum/YaBB.pl?num=1224729851/4#4 ). I got 3 years of service out of this sling, but the release cord sheath wore through last year and I have been patching it (with duct tape and cloth medical tape) since then. The core of the paracord is mostly intact, but it would not last much longer.
I usually sling on gravel playing fields and the ending of my overhand throws results in the sling being dragged along the gravel. I expect this is what wore out the release cord. The scuffs on the pouch are likely from (rare) ground impacts when I am doing underhand throws.
I did melt the end of the release cord, but repeated impacts with the ground broke the blob of melted nylon apart. I did whip it, but that only lasted a year and I did not bother to re-whip the end.