Whilst I'm aware that there is a command line tool to permenantly delete a TFS work item. (e.g. How to delete Work Item from Team Foundation Server)
Has anyone been able to achieve the same action programatically using the TFS 2010 API DLLs?
Shai Raiten has blogged about this here, where he makes use of DestroyWorkItems(ids).
It is advisable that you proceed with extra caution in your implementation, since this can severely mess your installation. One could argue that constructing such a tool deviates from best practices.