Lord Valve wrote:

OK, school-time: what you need is a GC Electronics 9337 "Plastone"
contact burnishing tool. This particular one is exactly the right size
for cleaning Cliff's (and Re-An and other Cliff's-clone) jacks. The
tool is flexible, and can be bent into any necessary shape to
reach the jacks' switch contacts. You insert a plug into the jack
to open the contacts, stick the burnisher between them, and
remove the plug, allowing the contacts to close on the burnisher.
You then saw the burnisher back and forth a few times to remove
the crud. THIS WILL NOT DAMAGE THE CONTACT SURFACES,
regardless of what you might see posted here by anyone else.
Finsh the job off with a shot of Caig D-5 or D-100 between the
contacts.

This does the sum store of ZERO for the switching contacts on either a Cliff or
Re-an jack.

I can't really see how it'll help on Switchcraft pattern jack either.

Graham