>maybe they need to see a couple days on a weekend behind bars as a sobering reminder

Anything I say that resembles stats would be made up, but just from my own anecdotal experience (being arrested and fingerprinted for failing to appear in traffic court, and friends spending the night in the drunk tank), I'd say this is exactly the wake-up call that most offenders would need to stop it.

The remainder are likely serious addicts or psychopaths who need medical intervention.