I am also agains using WD-40 or any other oil although those performs really well.( I have tried rapeseed oil as well)
I use this setup in my S3 for a year now:
Air is mostly enough but a bit of alcohol helps sometimes. It is really easy to spray more alcohol than enough that actually prevents chip evacuation. Once a month I wish I would have two nozzles instead of one but other than that the setup works flawlessly.
Flying chips can be an issue but the larger chips you make the less those stay in air. 
I was also thinking recently to make something -other than a dust shoe- that collets chips and allows me using air blast and vacuum at the same time. Probably a mini down draft attachment of some sort around my rails…