Safety strap for sling strap..

[Jack2013]

Hi all,
I remember back in one of the threads people there was mention of the damage that could result from using sling-style straps, and I remember a few people showed interest in constructing their own safety straps. I am interested in constructing some sort of safety connection to catch my camera if the tripod mount fails, but trying to figure out a strong-quick-release mechanism for where the cord attaches to the camera eyelet is proving problematic
Ideally I'd like it to be a carabiner but a search on Amazon has shown only metal type carabiners which would surely scratch/scuff the camera body, anyone have any ideas?

I have found that the cord used for raising and lowering blinds is ideal for thickness to strength ratio, just need to figure out the connection point to the eyelet, or I'll be tying knots and cutting them off every-time I want to go out/come back.