How to ensure Google bot can crawl unlinked pages

Site URL: https://heartpainter.com/

I remember reading that it's important to make sure every page on a site that you want indexed for SEO, is linked to at least one other page on the site in an outgoing path. Avoid dead ends that might stop all pages from being crawled. I have my product pages unlinked, because I can introduce them better on regular pages with summary blocks. (I'm using Wells template which doesn't let me show any introductory text on a product page.) 

The specific items in the blogs ("Stories" and "FAQ") already have links back to main pages.  

I could add a link to each product (in Additional Information) if that would be a good idea. What do you think?