Make one, thin pvc tube of suitable length + diameter & 2x plumbing end cap to suit, magnet, bit of string hole in top, drill one end for string, glue both ends into pipe with magnet inside attached to string.
Pull string to move magnet up tube releasing everything picked up on the flat end. No scraping stuff off the magnet needed.
Thanks chaps, I have got an evolution one for collection the swarf around the drill and saw, and yes, there good. I want a wider floor type (back is not as good as it used to be) I was using a nibbler the other day and the chips from them go everywhere, unfortunately one of them ended up in my dogs paw - Those vets certainly know how to charge !!!
I have two: a roller push along type for the floor, which is largely ok, and a wand style for picking up off machines etc. Roller type is fine where it can get to but misses the edges, the wand one is good, but tends to magnetise vices & clamps.