A chazzed banger is a term for a quartz nail that has residual buildup/staining from dabs taken out of it. If this happens, don't worry.
Method 1: Burn Off
The burn-off method is pretty straightforward but there are some things you want to note to do it right. (Hair is wet lol)
Get the banger red hot from the bottom
Move the flame to the affected areas, making sure not to spend too long concentrating heat in one place - especially near the joint.
Inspect to make sure there aren't any black flecks left
Method 2: Isopropyl Alcohol and qtips
This is a "safer" method that I would use if I had a very expensive quartz banger - or if the burn off does not work. You should also do this about once a month even if the bucket of the banger is clean in order to clean the neck of it.
Put isopropyl alcohol in a sandwich bag
Add rock salt (optional, but helps a lot!)
Shake hard for 3-5 minutes
Take banger out of bag - do not rinse yet
Use qtip to help clean any remaining problem areas
Reshake and repeat if needed - sometimes certain stains REALLY don't want to come off.