I understand. When I was researching about Icelandic Runestaves, I realized that there's a considerable number of runic charms to detect both thievery and adultery, they seemed to be at the top of the concerns in shamanic cultures in Europe too.
What I find most fascinating about this information is that the people thus marked can experience very tangible effects, very quickly. Have you personally met witch doctors able to perform this service? They must have amazing stories.
Not directly. The truth is you will not know who can perform such a service unless you specifically want such service. I have never (and will most likely never) had reasons to visit witch doctors but I know they abound. I do not think I will even visit them for research purposes.