Congrats on your first Barber !
It's totally up to you but ...
If that was my coin I'd put it in an electrolysis bath.
It's a safe and non abrasive way to clean encrusted Silver coins, aluminum Tokens and Relics.
It only attacks the foreign matter ( aka crud ) on an object.
But be careful not to leave the coin in to long because once all the crud is gone - it will start eating the silver (only like if you forgot it overnight).
I would guess that all the crud would just fall off your coin under running water after only 15 to 30 minutes or so in the bath.
I've used mine countless times to remove heavy crud, asphalt from driveway coins, etc.
You can probably make your own Electrolysis bath with a few things you already have laying around your house or garage.
It's safe to use, easy to build and it's free.
If your interested, you can find instructions on how to build one on the net.
Good Luck !