White pill?I see online what is called the magnetic stir bar magnetic stirrer. But the picture shows it as a straight piece. What i had was shaped like a cross. Is this straight one ok if i cannot find the other one. Why did the shape change?? Not sure why what i tried did not spin? Does it need to b magnetic snd if so how about the back of a fridge magnet. Those round disks??? Or am i being silly?