Jason, I put a computer hard drive magnet on the oil filter of my Toyota Hilux pickup. It stayed in place till the next oil change, when I opened the filter can to look. I could see the outline of the magnet on the inside of the filter can. Just a dark outline that disappeared as soon as I touched it. So the magnet was collecting steel particles from the oil, but I don't know if it has any real world benefit. It certainly can't do any harm on an external filter, but I'd be reluctant to put one inside the sump of my bike.