Is it just me or the idea of trusting a random IP as your authoritative DNS server sounds like a phenomenally bad idea in terms of security? At least, when you pay for a service like UnblockUS, there's a contract and a certain understanding of accountability, which you don't have here...
Agreed, it'd be worth trying with a set-top box of some variety where almost no data of consequence is being shared other than the aforementioned services but I'd be too wary of phishing for anything other than the most minimal of usage.