Cleaning amp/preamp

Hello whats your take on cleaning 

pcb board and internal sensitive parts of tubes circuit/sockets

all the pcb of old amplifiers/preamplifiers that have oily pcb board and other internal parts with :

isopropyl alcohol 99%

or WD 40 Contact Cleaner (not normal wd40) this one is vaporised after short time.

thank you
 

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