Comment by cosmotron
You can still get to product reviews directly and search them. Here's an example:
Product page (copy the identifier at the end): https://www.amazon.com/Long-Thanks-Hitchhikers-Guide-Galaxy-...
Review page (paste the identifier at the end): https://www.amazon.com/product-reviews/B001OF5F1E/
This seems to bypass all of the LLM stuff for now.
Pretty good! Unfortunately it does not include the Q&As, which are often just as useful as the reviews.