Because lots of our shifts became longer (more early starts with the same core finish time, more late stays with the same core start time), we're working more than the target hours per week, so we generated TOIL from our WP automatically for the first two years until the OR was raised. We had the option to sell that back.
I guess that's what the 'bung' came from.
Oh, and one is a tea drinker, so one has not sampled the other offerings, but one classes the free tea as slightly more palatable than what one assumes horsepiss to taste like.