I have one of those and have used it for cutting gift wrap. It never occurred to me to try to cut fabric with it, but I may have a go if I can find the thing. Can't remember where I got it, and it's probably stored in a Christmas box and will turn up again in 11 short months.
Editing to add that I checked Amazon, and double edged razor blades are still available. Probably they're in every corner drugstore, but don't you wonder who still uses them?