I cleaned mine for the first time at 45k (about the time I found this amazing site). I can tell you it made a huge difference. The most noticable improvement was throttle response. It probably restored lost horsepower as well.
Do not use brake cleaner (as it may be too aggressive) electrical contact cleaner or MAF cleaner is a weaker solvent and better for the very thin thermistor wire. CRC makes great cleaners for this. Just spray it in all of the orifices and that