I own an Iwata Eclipse airbrush, and one of the things it says in the maintenance manual is "requires periodic lubrication". The kit didn't come with any form of lubricant, and while it specifically states "do not use WD-40 or similar", it doesn't say what *to* use. Any suggestions as to what to use, and where to use it? I'm assuming the trigger assembly, and the needle bearing maybe? or back in the barrel where the needle chuck rides?