Easy to magnetize steel probes with so many magnets around, even the Fluke TPAK meter hanger. I see no reason to not demagnetize (degauss), I use my old analog tape demagnetizers, such as head demagnetizers or tape erasers. An old fashioned soldering gun works, too, if it has a big heavy transformer and a way to get the item near enough to it (not the soldering gun tip). My tools often get a little magnetized, such as getting close to a loudspeaker magnet. I've never tried one of the permanent magnet devices linked.
This also means your resistors have cheaper steel wire (probably clad with copper or the like) which I think is not optimal.