I have used various methods to clean the sensor. I would always start with a rocket blower, because it doesn't involve touching anything. Make sure the camera is upside down when using it.
If that doesn't work, it usually means that the dust or other stuff is stuck to the sensor (lightly or strongly). I have tried various options for that situation:
- sticky pad (I use DustAid -
Sensor Cleaning Kits for DSLR & Mirrorless Cameras | Dust-Aid - but gel sticks work on the same principle)
- artist's brush electrostatically charged using canned air (needs to be a high quality brush that won't lose bristles, kept in a sealed zip locked bag facing the same direction and not used for anything else)
- wet cleaning (high quality swabs and Eclipse or similar cleaning fluid)
Each of these can be effective. (A loupe with a light is handy to see what you are doing.) If the particles are not stuck on, the pad and the brush are about equally effective IMO. There are downsides of each. I have had sticky residue left on the sensor from the pad on occasions. With the brush, there is some risk of damage from dragging the particle across the sensor (e.g. something abrasive like a tiny grain of sand), although overall it's probably safer.
If you live in an area of high humidity or if the particles are otherwise likely to be damp and stuck on fast, or if other methods fail, you will need to resort to wet cleaning. You need to be very careful - use the swab only once on each side and don't use too much fluid on the swab.
When l couldn't get Eclipse a couple of months ago, I ordered a VSGO cleaning kit (
https://www.amazon.com/VSGO-DDR15-Camera-Sensor-Cleaning/dp/B00THAT6HM/). I used it this week and I have to say it was excellent. At one point a drop of excess fluid from the swab got on the sensor, but it left no residue.