I have tried using this query that I found for deleting All products, have changed it a bit. But it deleted all attributes of existing products.
DELETE relations.*, taxes.*, terms.* FROM wp_term_relationships AS relations INNER JOIN wp_term_taxonomy AS taxes ON relations.term_taxonomy_id=taxes.term_taxonomy_id INNER JOIN wp_terms AS terms ON taxes.term_id=terms.term_id WHERE object_id IN (ID1, ID2 ... 500 more IDs); DELETE FROM wp_postmeta WHERE post_id IN ( (ID1, ID2 ... 500 more IDs); DELETE FROM wp_posts WHERE `ID` IN (ID1, ID2 ... 500 more IDs);