How to keep secret products hidden from suggested products

I’d like to offer some secret product that are only available via link. I thought I had this nailed down by enabling the no search engine metafield. It turns out a regular customer found the secret product as a suggested product. Can a custom metfield be created to hide the hidden product from the suggested product?

How can I keep a product secret or hidden with a link only? This link will be used in an ad campaign so I can’t use an app that creates a password to access. I tried turning off all of the store options but then the link doesn’t work.

any help would be greatly appreciated

@CJH1
you can append a secret URL to your ad campaign
something like: /products/my-super-secret-product**?_secret=this-is-a-secret-page**

Then create a product template ONLY for that specific secret product.
Add the following code to the product template.