Sorry, I don't believe it just because a couple of researchers, presumably with an agenda or a desire for further funding of their anthropological tintinnabulations, have written about it.
WTF is wrong with you? I live here, I've suffered under white rule and my entire family was a struggle family so I've got no agenda. The fact is that this is a belief that is shared by many of the locals here :-( Why don't you believe what newspapers, researchers and people on the ground are telling you - these folk are still stuck in the stone age in many respects. Grab any local newspaper you want and see for yourself the pathetic beliefs these people have:
Virgin cure belief
Another one of many
Here's official african government admitting to the baby-rape problem
How about bullet-proof vaseline and other stupidities?
Results of the official inquiry into the massacre
Strikers use body parts from security gaurd for their muti
Cutting up a 6 year old girl for body parts for their muti before they even killed her.
In fact, there are too many stories in the courts to even list. You no longer have the assertions of a couple of anthropologist's, you have the statement of a born-and-bred african who is living here, you have official reports of cases in courts and you also have independent newspapers all verifying the same facts.
Maintaining your skepticism in the face of all this will just make you look foolish. These thugs from the above stories aren't ignorant; they've all completed high-school (equivalent to a US HS diploma) and many of them even have tertiary education. It has become abundantly clear that the problem cannot be solved by relieving these idiots of their ignorance with education; the problem is not ignorance, it's stupidity.