Delete all product belong to category
<?php
$deleteAllProduct = function() {
$products = Mage::getModel('catalog/product')->getCollection();
foreach ($products as $product) {
try {
$product->delete();
} catch(Exception $e) {
echo "Product #".$product->getId()." could not be remvoved: ".$e->getMessage();
}
}
};
//$deleteAllProduct();