This would lead to less compliance.

There are lots of people out there who would happily pay fines or not get deposits back if they didn't have to do the less glamorous parts of the event. You have to take something away that they actually care about.

If a camp does a really bad job at moop cleanup, Burning Man organization talks to leads to understand what happened. Frequently what they will take away is the camp's placement in the event, or sometimes even the ability to attend the event as that camp at all.

For reference: I am one of the leads for a fairly large and famous Burning Man camp. We camp on Esplanade most years. We do exactly what you proposed: We have deposits, and the more people put into the camp before, during, and after the event, determines if we offer them a refund and an invitation to camp with us next year. One of the factors is if you help us during setup and strike.

An invitation to camp with us guarantees them a ticket at one of the cheaper tiers. We have plenty of campers that come in, pay the dues, do nothing for the camp, are generally useless during the event, and bail out leaving a huge mess.

Conversely, we have a very small (10-20%) team of highly dedicated individuals who stay past the event and pick every piece of string, fuzz, fluff, lag bolt, rebar, and debris out of the dust and take it out. These people get nearly their entire camp dues back. If they attend next year, the social capital that they've built doing so compounds into them becoming increasingly popular and famous on Playa.

If there's one thing that Burning Man has taught me, it is that very few people are motivated by financial incentive. If you really want to motivate someone, figure out what they genuinely desire. It's rarely money.