I cut uncoated Food Lion paper plates in to strips. Then halve those.
Denatured alcohol 92% from Dollar General.
An ignition points file found in my first EM (Klondike).
The card stock of these plates match Business card stock.
The irregular ridges pressed in to each plate helps.
Very light strokes from the ignition file after cleaning, just the Crown of the point, clean again.
Of course after first tightening the switch screws.