From the article:

   Since the third party service conducted rate-limiting based on IP
   address (stated in their docs), my solution was to put the code that
   hit their service into some client-side Javascript, and then send
   the results back to my server from each of the clients.

   This way, the requests would appear to come from thousands of
   different places, since each client would presumably have their own
   unique IP address, and none of them would individually be going over
   the rate limit.

Pretty sure the browser Same Original Policy forbids this. Think about it- if this worked, you'd be able to scrape inside corporate firewalls simply by having users visit your website from behind the firewall.