Slipping magnetic cards

[Sylvain Cote]

My trick for slippery or oxidized magnetic cards is to rub them with a white gum pencil eraser from staedtler.
It worked most of the time on all magnetic card types, the short ones (65/67/97/41) and long ones (71/75).
You must hold them very hard on the extremities when you apply the gum, because if you do not, the card will follow and bend. When that happen it is over for that card.
To solve the issue I have made myself a card cleaning jig using a stainless steel ruler (cut at the appropriate length) and strong paper clip to hold the card on each end.
Sylvain
edit: typos