Chaning linked to duplicate

Is there a way to do a mass change of all linked products in my catalog to just be duplicate listings and not linked listings?

I want to be able to do sales for a category, but if a product is linked, zencart will not let me apply a sale on items that linked in a category, unless i do link all the master categories / products. So I would like to just unlink all my products at once and make them duplicates.

I have about 700 products in my retail store and a good amount of them are linked. Would hate to unlink them all by hand.

Any advice would be great.

No easy way to do this: linking products is done simply by adding entries in the products-to-categories table, while duplicating a product adds duplicate entries in the products, products-description and products-to-categories tables (and others if you have attributes on the products). It might be possible to write a custom script for the task, but that's the only way other than manually.