Spray liberally onto the MAF sensor (the metal parts and in the crevices) and leave to dry in air (or dry with a hairdryer set on cool if you're in a hurry)
No need to take the sensor out of the MAF housing - just use the straw provided with the spray can - the pressure from the spray will blow off any detritus (pollen/dust particles) and the IPA removes the oil and grease that can collect on the sensor (even if you don't have an oiled filter. Ever looked in the entrance to your Y-pipe? Then you may have seen a small pool of oil there - I believe this can coat your MAF sensor in mist form over a period of time)
Just cleaned my MAF with it and the car runs super smooth now (was getting a little jerky/hesitant at certain revs) - it's like having a brand new MAF.
DO NOT do this while the MAF sensor is hot/warm - only do it when the MAF is cold or at ambient temp. (you'll knacker the hot-film sensor) and DO NOT let the straw touch the sensor (I killed one by wiping it with a cotton-bud once!) - position straw a couple of cm's or so away and spray for a good few seconds. This is much better than an IPA bath - really cleans the sensor and revitalises the MAF.
Cost me £7.99 for the can (from Maplins)