manufacturer/dealers recommend against cleaning MAF, but then again, they are the ones that sell and install new ones at $150+labor.

i soak mine in a shot glass of cleaner for a 1/2 hour then air dry.

MAF elements can be coated by injested baked on products that prevent cleaning thus require replacement, case by case judgment basis.

look at the elements with a 10x power magnifier before and after cleaning.

search the Aero and other Ford forums for pros and cons of MAF cleaning, lots of info using the search function.