Stephané Dion eats a hot dog with a fork and knife.

[Michael Bluth]

Do an experiment. I swear to you that when you eat any kind of french fry gravy or no gravy with a fork as opposed to your fingers, it tastes different. I think the dirty from your hands is that extra flavour missing when you use your fork.

I wash before eat

I generally do too.

The "dirty" is open to many interpretations...