Are there special cleaning products to wipe away grins and smirks?

Yes, it's sold by Dope-Slaps R Us....;-D...

Well, you can take it off one of two ways, the easy way or the hard way.  If they won't voluntarily wipe it off when you ask, just take a big swing and use your Arm & Hammer it off their faces.  Works great every time.

There's one.  It's called humiliation. :-)

Nice play on words!

Thank you Nimitz, but I just now realized I should have said if someone wanted to take the easy way, they could use Easy-Off. Bummer. Oh well. Lol

Windex?

Unless it is someone else.  Then it is sweet schadenfreude.

Do you have the authority to make such a request of another?  Maybe the grin is deserved.

Yes, muriatic acid. Better known as hydrochloric acid. 

As Grumpy Cat notes....

Acid. Dig it.