Cleaning Brass Variable Capacitors

[Ron Evans]

Hi,

I have three very old brass variable capacitors, one of which has a fair
amount of corrosion showing on the outside of the outermost rotor
plates.
I am building a super-duper crystal radio and want to make these babies
shine as bright as possible...just can't stand the yukky black
corrosion.

Does anyone have a favorite method and chemical(s) you use in cleaning
items such as this?  Some authorities (?) suggest GUNK and/or carboretor
cleaner. Are these harmful to the fiber spacer used to separate the
plates of both the rotor and stator?

How about such commercial products as Brasso?

Are there any special "lookouts" that I should observe in cleaning these
old gals?  How about pipe cleaners to clean between the plates?

All ideas deeply appreciated!

Ron - K5MVR