It is pretty easy to clean up the database with the following code:
$mp = Mage::getModel('catalog/product') ->getCollection(); foreach($mp as $p) $p->delete();
Of course the following things should be included at the top of the script:
include $magento_dir.'/app/Mage.php'; Mage::app('admin');
PS: Please note the “admin” in the magento app, instead of the “default”. It's required, in other case you will receive the “Cannot complete this operation from non-admin area.” error.