You can also experiment. Spread some mustard on the blade and then layer on some ketchup. The ketchup will get into the spaces the mustard missed. Oh and I have just shoved a smaller bladed knife into a potato and let it set for a couple three days.
Oh and if the mustard is cold and the ketchup room temp it will work out better. The mustard will go on thicker and the ketchup thinner which is what you want.
Now I feel like you are just messing with me. We are still talking about knives right?
