Easy way to clean surface contamination from 4mm banana plug and spade lugs

[Kiriakos GR]

1) Cleaning of surface contamination at 4mm banana plug

Your 4mm male banana plug this no matter in which factory was made, at the pin side will have the spring loaded surface.
The cleaning of the surface it can be made by the use of pencil eraser which this is bright new and never used to erase pencil. 
Spring loaded surface this is mounted of a master pin, this area it can only cleaned with injection of isopropyl alcohol, the one for medical use this is rather expensive but Teslanol Electro clean spay this will work too.

2) Cleaning of surface contamination at spade lugs
Here you may simply use a pencil eraser, there is no need for using any chemicals.


Cleaning of female banana plugs this is tricky, especially of the ones over a multimeter.
Some quality made multimeter they use rubber O-ring to prevent insertion of water or other liquids.
One Cotton swab this can be inserted, but for best results this should be wet just a bit by isopropyl alcohol.
Use of compressed air this is the very first step of cleaning process, then as soon Cotton swab it does it job then the multimeter it should stay 15 minutes to dry with no probes attached. 

Nickel plated or Gold plated parts all they should be cleaned by a gentle way,  the sand paper this is for idiots to use.