There is a function that deletes all products in the database:
http://your_site/ViArt_Shop/admin/admin_products_delete.php
Replace 'your_site' and 'ViArt_Shop' with your own parameters.
We do not have a general link to this script to avoid users accidentally deleting all products in their database.
WARNING: Any deletions can not be recovered. We would strongly suggest that you back up your database before using the script to allow a 'roll back' if required.