Manual:PurgeExpiredWatchlistItems.php

Details
purgeExpiredWatchlistItems.php is a maintenance script that deletes expired rows from the and  database tables.

Options
This script doesn't have any of its own parameters, and the most useful of the generic parameters is probably, which determines how many rows will be deleted on each run (defaults to 500 ).

Common error
An error is thrown if is not true. Set  to enable.
 * Watchlist expiry is not enabled.