The company I work for sells several products. One has a title that lines up very well in the One Ring poem from Tolkien's LOTR. I would essentially be replacing the phrase One Ring with the product title, and either leaving the rest the same, or perhaps a slight modification to the last line. Is there any way this falls under fair use or would I need to get permission to do this?
The product in no way relates to anything Tolkien or fantasy or fiction for that matter. I don't believe it could be seen as an endorsement.