Clearing my Products Completely

My client has had a complete rethink of their category structure. This is a client with over 40,000 products. We have every single product in the new structure ready to upload but I really need to just dump everything in the existing product tables so far.

I realize this could be dangerous for some people but we really want to start fresh and I don't want to reinstall the cart. Can anyone give an an idea of how I can drop every product? I've learned that deleting them through admin really doesn't make them go away.

I am able to execute sql queries through PHPmyAdmin but I don't think it's a simple as dropping the products table.

Any help is appreciated!

I should probably also mention that there is nothing complicated about any of these products - no attributes and nothing other than straight across product creation.

Deleting products and categories from admin does delete them completely, but it would take a long time to do with that number of products.
To do it through phpMyAdmin is pretty simple - but I'd make a backup first just in case the client changes their mind again.
From phpmyadmin, select the database so you see the complete list of tables.
Select each of the following tables:
products
products_description
categories
categories_description
products_to_categories
products_discount_quantity *
products_attributes *
products_attributes_download *
specials *
featured *

• only necessary if you have any data in them
  Once they are all selected, use the dropdown at the bottom of the list and select EMPTY - that will delete all of the entires in the selected tables.

Yep - made a good backup. Thanks so much!