You are obviously not a manager then if you can't work that out!
Anyway, who was talking of strike action? How about an overtime ban?
That should focus the minds of the higherups in a heartbeat.
You should make a big beat up in the media for the month ahead of the ban, run with the ban for two weeks to a month, and let the chips fall where they may.
You might have to "discuss" the nature of the problem with those that can't help themselves coming in for that extra cash, but you get them in every organization, and better still, everyone will know who they are.
Bring some media into the centre on a "fact finding mission". Take photos with your whiz bang mobile phone and post them on the internet of empty consoles (under an assumed name of course)
Take the fight to the bar stewards, stop standing there getting hit!
Trying to act all mature, long suffering and reasonable hasn't worked in the past so why would anyone think it will work in the future?
Short term pain, long term gain....for everyone.