How much time to clean out a locker ?

If you are a newcomer to auctions this is one thing that is a real concern, especially if you buy multiple lockers at one or more locations.

What is the "norm" where you buy?  24 hours, 48 hours, etc.

Old-timers will have good working relationships with facilities that will expand that to a week or more...care to share how you swing that?

Most facilities say that you have to have the unit empty by the end of the day. I have found that only one in my area is truly that strict (they have a 100% rental rate and normally already have the units rented before auction). I have a place to bring my stuff to so I have never taken more than two days to empty a unit. A couple of facilities give time based on how much is in the unit.
For newbies just remember if this is long term for you make sure you leave the unit spotless. I always leave them very clean and the managers/owners remember me for that. I have been told several times that no one ever leaves a unit that clean. (My mom usually even knocks down the spider webs. It's her pet peeve) The managers/owners really appreciate being able to rent a unit right away without having to do any work. When they start remembering you they tend to work with you more.

public has been flipping back and forth between 24 and 48 hours , most of the others 24 hours

They are pretty lax here, most of us can get up to a week. More so if it is slam full.

48 hours seems to be the norm for my area. Occasionally 24 hours. As calcoastgal said it does help to leave the unit spotless because they do remember. There have been a couple times where we have needed an extra day or two and generally they will give in. I recently went to an auction where gave a week to clean out. Didn't buy one there but that would be great.

The average here seems to be 48 hours, and sometimes longer if it's a bigger unit (having different lengths based on the size and quantity in the unit).