You can now delete an arbitrary set of products directly with a spreadsheet edit. To do so just upload a spreadsheet with two columns, one to identify the products or variants and the other containing the text 'delete'.
As with in-app edits to delete products, this action cannot be undone. In many cases is may be better to set the products to the 'Archived' state instead.
Learn more about bulk deleting products and variants in Shopify.