Quite a few of the people who frequent Vodou, Rootwork/Hoodoo or African Traditional Religions forums are looking for a practitioner to do magic on their behalf. Quite a few others are practitioners seeking clients. If you believe in Adam Smith, this may seem an ideal situation: a marketplace where buyers and sellers can meet and make arrangements for private workings. The truth is that the spiritual marketplace, like any other marketplace, is fraught with danger and those who stumble in blindly are not likely to fare well. And this is true for those on both sides of the equation: a naive seller who thinks s/he has stumbled upon the pathway to riches may fall as hard as a naive buyer who is convinced that s/he is one wanga away from a lottery jackpot and early retirement. If you are going to engage in spiritual commerce, it behooves you to set some appropriate boundaries.
"Caveat emptor" always applies. If you are seeking a houngan, rootworker, iyalocha, etc. you should do some research and check their reputation. Everyone has a few disgruntled clients and there are certainly many practitioners who will try to build their own reputations by tearing down others. But where there is smoke, there is often fire. If there are numerous accounts of a teacher engaging in sexual, physical or financial abuse, you may want to take them seriously. (And while sex magic is a valid path, it is emphatically NOT a part of Haitian Vodou or any African traditional religion. If someone suggests the solution to your spiritual problems can be found in his pants, or tells you to strip naked so he can give you a "spiritual bath," run, don't walk, away). If you find your worker-to-be has a history of using information gained in confidence to embarrass dissatisfied clients ("Of course your wife wouldn't come back to you. It's not MY fault that you're an unemployed alcoholic!" etc.), you can assume that your information will be used in a similar fashion.
By the same token, I also recommend "caveat vendor." If your prospective client sends you pages of word salad talking about how aliens from Mars and the Zionist Occupying Government are conspiring with her ex-husband's new girlfriend, you may want to think twice about taking her on as a client. If someone wants a wanga so his girlfriend will "jump when I say jump and do everything I tell her to do like the bitch she is," you accept his money at your own peril. One of the best way to avoid loud, disgruntled clients is to avoid people who need a psychiatrist more than they need a spiritual advisor. There is no shame in saying "I don't think I can help you: best of luck in your search." There is shame in taking financial advantage of mentally ill or desperate people. And not only is it unethical, it's bad business. You'll soon find that those clients will take up an inordinate amount of your time and energy - then turn on you when you're unable to provide them the healing they so desperately seek.
As with anything else, a little bit of common sense can go a long way. If you spend as much time and energy researching a rootworker as you would researching a prospective dentist or caterer for a big party, you're likely to avoid the worst case scenarios. If you treat your obligation to your clients as a sacred duty and respectfully decline to take on people whose needs are beyond what you can offer, you're likely to avoid most public blow-ups and mud-slinging. In either case ask yourself "I am going to be spending several hours with this person: would I feel comfortable sitting beside them on a long bus ride?" If the answer is no, both of you need to look elsewhere.