For a ferromagnetic material in the hysteresis loop, when increasing field from H=Hc, its magnetization (M) will saturate. But if we decrease field instead, will M decreases clockwise according to the loop? How can we make the ferromagnetic material back into the initial state (H=0, M=0)? One way is to go through TN, but some material's TN is very high. Is there any other practical method?