Do you mean the DE blades or the shaper blades for the AC? Many years ago I tried to strop the AC with a blade in it and it didn't work. Many people find the DE blades "too sharp" and they are better off with a a lesser blade, or maybe just using the Feathers in a very mild razor. All blades can be slightly blunted by drawing them carefully across some soft wood, making a tiny score in the wood. It's easy to ruin the blade, but it certainly makes it act as if it's been shaved with a time or two.