What do you mean by poisoned? For me it's the contrary, I switch to Google Public DNS whenever I'm using an ISP with "lying" DNS (returning a search page instead of NXDOMAIN).
The basic technique takes advantage of the fact that DNS allows you to provide additional information in a response so the response for ev1l.hax0rs.org can return a reply which says "This is handled by ns.reddit.com. Oh, by the way, ns.reddit.com is 1.2.3.4"; any server which doesn't properly validate that last part would add the incorrect ns.reddit.com record to its local cache and potentially use it to handle requests for other clients.
That's a better question for the original poster - I described the generic technique but haven't heard of anyone successfully applying it to Google Public DNS.
