How do I clean up the sessions table? I need to delete entries about anonymous user login from the sessions table.

I read what reported in 
https://techcommons.stanford.edu/topics/drupal/sessions-table-cleanup.

Which PHP setting in the page above ensures automatic removal of anonymous user login entries from the sessions table handled from Drupal? Do the suggested settings have any effect on that database table?
Go to your Drupal installation directory     /sites/default/settings.php and add the following line

ini_set('arg_separator.output',     '&amp;amp;');
ini_set('magic_quotes_runtime',     0);
ini_set('magic_quotes_sybase',      0);
ini_set('session.cache_expire',     10800);
ini_set('session.cache_limiter',    'none');
ini_set('session.cookie_lifetime',  10800);
ini_set('session.gc_maxlifetime',   10800);
ini_set('session.save_handler',     'user');
ini_set('session.use_only_cookies', 1);
ini_set('session.use_trans_sid',    0);
ini_set('url_rewriter.tags',        '');
ini_set('session.gc_probability', 1);