connector cleaning / deoxidising

[tyefighter]

hey guys 

i know this may seem like a simple question but i thought it best to seek advice from some of you guys that have been around the block and must have come across this before so any help will be greatly appreciated 

i have just picked up a couple of second hand mains cables and the prongs on the silver plated plugs are all dirty and tarnished. I took a look inside and although nowhere near as bad, could do with a freshen up too. Not looked inside the IEC plug yet, need to look it up to make sure i dont damage it on disassemble. 

so my question is what is the best way of bringing the cables back to their optimal best?

do i simply give the prongs a gentle rub over with Silvo and assume the wire connections are ok at their contact points?

do i disassemble the plugs completely and clean them up with Silvo or similar (recommendations welcome) 
maybe even clean any silvo residue off afterwards with isopropyl alcohol?
i have a sonic cleaner but i dont think the silver plating will like that too much

alternatively "insert your best solution here"

thanks again and excuse my ignorance