Backwash
To allow the liquid from a can or bottle to re-enter the vessel, complete with some of your own saliva. The soft drink equivalent of bumkissing a spliff. Backwashing led to the often repeated statistic that the last 10% of any can of coke is 50% saliva. Plainly bollocks, as not everyone is a scabby backwashing bronno.
written by Da*iel W*rd, Jo* Bly*h, approved by Log

Also called spit backs, for plainly obvious reasons, you idiot.
written by bl*e ann*, approved by Log

Also known as a backflush, often abbreviated in usage to a simple flush.
For example, "you lousy fucking shit, you've flushed me can".
written by Pi* P*mma, approved by Log