Good cloaking tools? It's called ignorance.
Any time an affiliate program gets someone like me involved to clean up the crap, people get caught. Tools like Search Monitor, Adgooroo, and Brand Verity catch shit, if affiliates are taking over brand ads. I've seen companies decide to let affiliates violate terms for an entire month, and then just refuse to pay and get free traffic.
From violating Google's terms, as soon as one someone pulling crap moves into the space of the merchants that I do work for, let's just say Google bans are handed out. Google's teams are extremely adept at catching cloaking once it's pointed out. Even the most sophisticated cloaking is easily defeated by someone checking it from regular search results from their home connection.
Yes, there's ton of places to get away with shit for long periods of time (like some shit I've done for 2 years now... and the only adwords account I've had banned was my 100% legit one, not my shady one).
If you're really going to do shit that's shady, and want to be assured of staying under the radar, fuck getting greedy with Google, and do it on MSN and Yahoo where shit is a lot harder to catch.