...use your coticules for anything other than razors.

I am honing this weird cutter tool for my mother, and arrived at the stage where I switched to the yellow to polish the bevels.
I was smart enough not to use my own stone for this, but used a stone which my mother bought for that purpose several years ago.
It turned out to be a thick piece of Belgian yellow with a slate backing.

I used too much pressure, or simply made a slight mistake in holding the knife, and tore a deep scratch in the surface.
I got rid of it by lapping, but you can image that this is a good way to quickly lose a good stone.

hones used for honing razors should only be used to hone razors I guess.