I thought of a good use for cheapy razors today.

Someone new to straight shaving could buy a GD, then file the edge down to the point of it being butter-knife blunt, but smooth.

Then use it as a safe "practice" razor. Lather up, work on holding the razor correctly, moving it correctly across the face, using the off-hand, etc. With a rounded, smooth edge, no damage done, but maybe some early awkwardness could be avoided?

I have to believe this idea has been tried, and must have failed, but I thought I'd put it out there and see what you think?