Hi Aniello,
Thanks for the access to the site. There was misunderstanding. I thought you have a problem with revoking access to the “Products” menu at /wp-admin, but you wish to manage view access to the products at front-end.
You are at almost 1 step from your purpose. Setting you made for products with category “Gioielli” is correct in case you wish to block view of post content (product decsription) but still leave post title (product title) available in the listings (catalogo or shop page) and product page itself (just without content). In case you wish to exclude product from the listing and fully hide its page, you need to select action “Return 404 HTTP error”
