Hello Phil,
Sorry to hear you ran into some issues! It looks like the double confirmation problem was the result of an error when the plugin was published to the WordPress plugin repo. That should now be resolved in the latest (0.1.2) version of the plugin.
If you’d like to remove all of the plugin data from your database, you’ll want to remove any meta value with a key containing “lfc” from the postmeta table, as well as any option containing “lfc” from the options table. That should remove all data used by the plugin.
Thanks!