I am not sure why, but I had always thought that sharpening a knife would be super hard.
Surprisingly, it is not hard to sharpen a knife using a coffee cup.
Yes, the only stipulation is the fact that the coffee cup needs to be ceramic.

Image By: Blainenp Via YouTube
[social_warfare]
This is a great idea, it works really well.
https://www.youtube.com/watch?v=oRVgxMTVsg4

