Use this hint at your own risk! Be sure to have some kind of backup available.
Here's how:
- Using Launchpad, create a group of items named 'Trash' and fill it with the shortcuts you're wishing to remove.
- Unhide your 'library folder' (See this previous hint, or use your favorite method).
- Backup your Launchpad database located in ~/Library/Application Support/Dock.
- Download any sqllite query editor (Navicat Lite is very good and free).
- Open the Launchpad database with Navicat.
- Run the following query:
delete from items where exists ( select i.rowid from items as i inner join groups on i.parent_id=groups.item_id where groups.title like 'Trash' and items.rowid = i.rowid )
The database is taking care of data consistency via triggers (triggers will remove images caches and reorder items).
The good point is that the (now empty) 'Trash' group will remain.
[crarko adds: I haven't tested this one. As mentioned in the hint, please be careful and have a backup handy before trying this. I have to say, Launchpad is one of those features I'm kind of 'meh' over. I have no interest in reorganizing the thousand-plus applications I've got into folders again. Maybe on a new machine.]

