This method has been tested and works. One of the reasons you want to do this is when you are testing Dataflow Import for products. When you specify images in a download, Magento only adds images - it does not replace or delete them.
The end result is that multiple profile runs will accumulate the amount of redundant images.
mysql> **truncate catalog_product_entity_media_gallery;** mysql> **truncate catalog_product_entity_media_gallery_value;**
Then from the command line of your Magento media / directory folder:
media/catalog$ **rm -rf ./product/**
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