Need to clean sensor - advice needed

Start with the method least likely to leave residue and work your way up:

1) Sensor's self-clean vibration

2) Bulb/rocket blower

3) SensorKlear pen

4) PecPad with Eclipse solution

in that order. If you use any method that physically touches the sensor (including #3 and #4), it will leave residue on the sensor which is visible under a lit loupe. For that reason I have only used a bulb blower on my NEX and only used the sensor pen or wet cleaning on bodies that do not have the anti-dust shake.

If you're using isopropyl alcohol, it will not evaporate quickly enough and leave residue. Eclipse solution is methanol which works better, but is toxic stuff so I would wear gloves while using it.