Craig,
I used the B string from a light acoustic set, .016" diameter for cleaning mine. The steel wire is firm, but flexible and did a great job--can be run all the way to the connector. I need to run to grocery store in a while, if i have a spare string i'll hang it on the door knob at your shop.
Earl

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Earl McLain
'02 C230 Kompressor
'89 560 SEL "Frau BlueCar" (retired April 2004)