Magento: How to remove all catalog products

Reset all product tables. Beware, below script will delete ALL your product data so do it carefully.

To remove all product go to the database and run the following query

SET FOREIGN_KEY_CHECKS = 0;

TRUNCATE TABLE `catalog_product_bundle_option`;

TRUNCATE TABLE `catalog_product_bundle_option_value`;

TRUNCATE TABLE `catalog_product_bundle_selection`;

TRUNCATE TABLE `catalog_product_entity_datetime`;

TRUNCATE TABLE `catalog_product_entity_decimal`;

TRUNCATE TABLE `catalog_product_entity_gallery`;

TRUNCATE TABLE `catalog_product_entity_int`;

TRUNCATE TABLE `catalog_product_entity_media_gallery`;

TRUNCATE TABLE `catalog_product_entity_media_gallery_value`;

TRUNCATE TABLE `catalog_product_entity_text`;

TRUNCATE TABLE `catalog_product_entity_tier_price`;

TRUNCATE TABLE `catalog_product_entity_varchar`;

TRUNCATE TABLE `catalog_product_link`;

TRUNCATE TABLE `catalog_product_link_attribute`;

TRUNCATE TABLE `catalog_product_link_attribute_decimal`;

TRUNCATE TABLE `catalog_product_link_attribute_int`;

TRUNCATE TABLE `catalog_product_link_attribute_varchar`;

TRUNCATE TABLE `catalog_product_link_type`;

TRUNCATE TABLE `catalog_product_option`;

TRUNCATE TABLE `catalog_product_option_price`;

TRUNCATE TABLE `catalog_product_option_title`;

TRUNCATE TABLE `catalog_product_option_type_price`;

TRUNCATE TABLE `catalog_product_option_type_title`;

TRUNCATE TABLE `catalog_product_option_type_value`;

TRUNCATE TABLE `catalog_product_super_attribute`;

TRUNCATE TABLE `catalog_product_super_attribute_label`;

TRUNCATE TABLE `catalog_product_super_attribute_pricing`;

TRUNCATE TABLE `catalog_product_super_link`;

TRUNCATE TABLE `catalog_product_enabled_index`;

TRUNCATE TABLE `catalog_product_website`;

TRUNCATE TABLE `catalog_product_entity`;

TRUNCATE TABLE `cataloginventory_stock`;

TRUNCATE TABLE `cataloginventory_stock_item`;

TRUNCATE TABLE `cataloginventory_stock_status`;

SET FOREIGN_KEY_CHECKS = 1;

INSERT  INTO `catalog_product_link_type`(`link_type_id`,`code`) VALUES (1,'relation'),(2,'bundle'),(3,'super'),(4,'up_sell'),(5,'cross_sell');

INSERT  INTO `catalog_product_link_attribute`(`product_link_attribute_id`,`link_type_id`,`product_link_attribute_code`,`data_type`) VALUES (1,2,'qty','decimal'),(2,1,'position','int'),(3,4,'position','int'),(4,5,'position','int'),(6,1,'qty','decimal'),(7,3,'position','int'),(8,3,'qty','decimal');

INSERT  INTO `cataloginventory_stock`(`stock_id`,`stock_name`) VALUES (1,'Default');

Note: Then you may require re-indexing all your indexes after running above query.
for that go to System > Index Management > Reindex all.