In answer to your question of 'what situation warrants 200% inspection'. No situation warrants 200% inspection. You can not inspect quality into a batch of material. All you can do is cull out bad product. Typically to get to around 99% confidence you need to do 350% inspection. It just doesn't make sense.
Now, to the practical side of things. Sampling schemes only work if you apply the scheme not the plan. An AQL plan such as the old military MIL-STD-105 only worked if you used rectification and switching procedures. That is, the specific rejected lot was 100% inspected and the plan went to tightened or loosened inspection based on past results. The sampling scheme was set to control quality levels over time, not for a specific lot of material. As Dave S. said, AQL plans should generally be used as short term stop gap measures to control quality to some tolerable level while improvements aree made. If you need to use sampling plans/schemes, there are many to choose from. As Dave S. recommends, I also suggest you get a copy of Ed Schillings book on acceptance sampling. IMHO it is the bible on sampling. It is a rough read, pretty technical. If you want something a little easier as a starter try Dale Besterfield's book on Quality Control. He dose a pretty good job of giving an overview of sampling plans and the inherent risks associated with them.
Just to muck up the works a bit, you need to evaluate any plan based on its risks. You should review the Operating Characteristic Curve (OC), and the Average Outgoing Quality (AOQ) and Average Outgoing Quality Limit (AOQL) to determine if the risks are accepptable.
Bottom line, you are better off spending resources on fixing the process than improving the sampling scheme. Sampling costs money and does not improve the product.
Hope this helps.