Both methods work, but like others here, I prefer to make sure they understand when it comes to food I'm the boss.
Mine big group are fed from a trough, and they have to let me walk to teh trough and dump the buckets before they eat. We go through cycles with this, I take the whip for a few times, everyone remembers their manners, I stop taking the whip. Overtime they start gradually becoming a little more pushy, so out comes the whip for a few days until everyone remembers, then we are good for a while.
Also it isn't the whip that is the magic, that just helps you stay out of range, the magic comes from you being dominant in thought, word, body stance and action. You have to believe that you are the boss, and then it's easier to make them believe it as well.