Ignition off, Philips screwdriver, take out the two screws, pull out the MAF, don't disconnect it, spray the sensing wires through the holes with carb cleaner or electrical cleaner, put it back
Don't rub it with anything, just let the spray to do the work. And it won't necessarily look dirty, but it will be
Cheers Joe. I'll give that a go tomorrow lunchtime at work, if it's dry