It's not the "sharpener" that doesn't work... it is the blade. Currently produced DE and SE blades are coated, and have a compound bevel. The old thick blades could be honed and stropped to good effect, but modern blades just don't benefit much from either. And that's why you don't see many new DE or SE honing or stropping devices. Plus, blades are so cheap it doesn't make sense to mess with them much. If you want to hone and strop, switch to straights. Or Rolls, or Valets or similar.
Stropping still tends to knock some crud off of the surface, which does not sharpen the edge but can extend blade life. It needs to be a decent blade to start with, though.
When I want a blade to last a week, I jeans-strop after each shave.