I used to use Schick injector blades, but they have vanished off the shelves in the last few years.
I see them crop up at Tandy on occasion, once I saw a 1000 brick of them and didn't take advantage, I regret that very much now.
I tend to get more cuts off the purpose built blades they sell as replacements for the strap cutter, in one position, but with the Schick blades I can move them around and get three new edges off one blade because they are longer. BUT, watch out for the over hang! That piece will ruin your day in a heartbeat!!! A good pair of jeans will become trash, a finger can get in the way, and not to mention your leg. Anything within reach is fair game for that little bit of metal.
The best? Well, I've used the hardwood one from Tandy for over ten years and its still going strong. Dont get the Stript ease cutter, its not worth the effort. Mine is in the bottom of a box somewhere.