hardly ever need to demagnetize anything usually I have the opposite problem I will need an Allen wrench or tool bit or screw driver magnetized for these I keep a small selection of button neo magnets in a wooden box When done I remove the magnet any residual magnetism left in the tool is fine by me if swarf becomes a problem just rap the tool against something to knock the swarf loose .
But I know that a lot of guys need their tools free of any residual magnetism your demagnetizer looks like it would fit the bill for that, good job