title: Change product visibility via PHP on Woocommerce 3+
body: <p>I have a feature on my store that allows me to auto-generate a product quote, after the quote's attributes, prices, and shipping rules, I create a new product on the fly.</p>
  
  <p>I don't want these products to show on my catalogue or searches, so I've been trying to figure out how to update the "Catalog Visibility" to Hidden.</p>
  
  <p>At first I was trying: </p>
  
  <pre><code>update_post_meta( $prod_ID, '_visibility', 'hidden' );
  </code></pre>
  
  <p>The meta is added, however, looking into it I found out that WooCommerce changed the way it  specifies if a product is visible or hidden:: below is from WooCommerce </p>
  
  <blockquote>
    <p><strong>Product visibility is taxonomy based instead of meta based</strong>
    3.0.0 introduces a new product visibility taxonomy; catalogue, search, hidden, featured, out of stock are terms. These are set to upgrade and help filter products in the catalogue during frontend queries.</p>
  </blockquote>
  
  <p>My issue is; how can I modify a taxonomy via PHP.</p>