as I was brought up in Brazil and also with the candomblé the "buzios" are familiar to me. I do not really work with them, though I am studying them for years now. There had been strong forces telling or showing me that it is not yet the time to use them. The shells are no cards, never forget that and be very careful in using them. Their roots go down thousands of years and its not western culture. There are many forces related to them that in our culture are felt as dark.
Originally you would have to be initiated by a priest to be able to use them without danger, and even if I dont follow that line of thinking, I have known that you can definetely follow their way by yourself, but it is a way that is serious about it. You can play around with cards, but playing around with the shells will always call forces that dont play. Dont understand me wrong, I am not initiated and do make experiments with them. I just tell you that the worst moments of spiritual fear I have had in the last years came out of this door. I will go on, and I know it is the right way, but it is a long way connected to sacrifice. But at its end I hope to find knowledge without artificial instruments (like horoscopes, cards etc.), but be able to read reality´s symbols themselves, stones, clouds, traffic lights, whatever. The way of the shells goes there. Originally the shells have to be initiated with blood. This, I think, is over, but the idea remains the same. Do you have an idea of the world of Santeria, Voodoo, Candomblé? That is where their forces live. Tarot is mostly a philosophy comparing to the shells, which are not at all brainy, but very real.
I dont want to go further into the topic publicly, but please feel free to write me privately if you like.