If i recall correctly, 3D iterative tresholding is one of the functions included in the 3d ImageJ suite plugin. This plugin has been published (see link). The paper itself is not very detailed but the supplementary info is quite extensive and might contain some info on the iterative tresholding bit.
I have already read all the aforementioned infos and are not as technical, as I wanted them to be. Since I might use this segmentation method for scientific publication, I would rather to have more details to explain the method.