Coconut butter is a mixture of very finely chopped coconut, (kind of powdery) mixed with coconut oil. Sort of like peanut butter, except with coconut. Your project should be interesting.:? Keep us posted.
Yes indeed, that is interesting. Can you post your whole recipe by the weights of all of your ingredients, including the lye, the coconut butter, the other oils, water and any other additives you put in? That will help determine whether you had enough oils to fully convert the lye. The best test though will be to let the soap saponify for a day or two and then do a zap test. Depending on how much you used your soap might be lye heavy, but given enough time that can rectify itself.