Re: Cleaning the maf ???
Brake cleaner is probably the better bet. (it's usually made from iso-propyl alcholol or perchloro-ethylene - used by the dry cleaning industry).
Most MAFs (Alfa included - presumably), heat the sensor wire to red hot for a couple of seconds - or less - after the engine is switched off. This is meant to burn off any residue, and presumably would get rid of any unwanted WD40 after spraying. If the WD had absorbed the dirt, then the burning process would probably successfully do the business.