So you deleted your trash in your viewer and then logged out thinking it was all done and dusted? The next time you log back in all your deleted files are back. How did that happen? The simple answer is that in the OSgrid you have to delete your trash whilst in world. Then you need to logout and login to the website at https://www.osgrid.org/ and delete trash from there.Just tick the square by Trash and then hit that Empty button and magically your trash will have gone the next time you login.