You have to go bid on it once you force the sale. In this economy the auctions aren't that competitive, picking it up like that will almost certainly be cheaper than the cost of conducting a trial with expert witnesses to establish your AP claim, which I guarantee you will fail in the end anyway. Plus you have 3 years in it this way, instead of 7. If you're going to do it, go the tax deed route. FYI, if you have a particular house you're targeting, there is nothing stopping you from accumulating prior years' certificates directly from whoever bought them. Effectively, there is no reason you even have to wait the 3 years if the buyers of prior years' certificates will sell those to you. This AP thing is utter nonsense, I promise you're wasting your time with it.
I see Stephen has been asking the same question I asked but never got an answer to; Show me one single case where one of these squatters has been awarded a free house. If this is such a slam-dunk legal strategy, why has it never worked even once? I think even the Twinkie Defense managed to get someone manslaughter instead of murder, but this AP nonsense has never worked even once. And I don't mean accidentally putting a fence 4" on your neighbor's property, which is what the statute is supposed to be used for. I mean squatting.