Speed Density equipped vehicles such as my 92 E150 don't suffer from the same epidemic that later MAF sensor equipped vehicles do, the MAF sensor is rather delicate and has very sensitive components which work together to measure the amount of airflow entering the engine, when the MAF is calibrated at the factory these tiny sensors located inside the MAF are clean and free of any residue but after time they become contaminated and covered with debris which causes the sensor to give an incorrect measurement which in turn causes the ECU to deliver the wrong amount of fuel to the engine, could be too little or too much, either way it is not good and you are losing both performance and mileage, the only oxygen sensor approved MAF cleaner that i know of is made by CRC and is available in spray can, be careful what you spray down the intake tract of the modern auto as you can do more harm than good if you're not careful, oxygen sensors can be rendered useless by spraying the wrong thing down the intake..
BTW, whatever you do DO NOT REMOVE the honeycomb shaped piece that rests inside some MAF sensors, that is there to straighten the airflow and is necessary for the MAF to work correctly, the MAF sensor is kinda sensitive to changes in airflow in and around it and prefers a smooth laminar flow.
If you change the intake tubing connecting to the MAF on your vehicle and it is different than what came with then you have changed the calibration and the MAF must be re-calibrated, so many people with their CAI's cold air intakes doing more harm than good, don't have a clue what that expensive chrome pipe did to the engines state of tune..

 

I clean mine either after an oil change or a few miles after changing the oil based air filter.

Although your vehicle will differ from this example, if gives the general idea on how the MAF can be cleaned.