I would like to display customer reviews from another website (with their agreement) own my own site for certain product pages.
Using these 3rd party reviews would be helpful for users, though there's an issue with duplicate content as I'll be republishing these reviews from the other website.
I don't want to noindex the whole page as many of these product pages already rank well.
One option I'm considering is to place the review content in an iframe and then block the iframe's URL in the robots.txt, though I'm unclear as to whether this would be frowned upon by search engines.
Is there a best practice, recognized and accepted by Google, for noindexing or blocking crawling of certain sections of a page?