I was surprised on how fast my camera's sensor required cleaning. Switching lenses in the field is something that tends to attract dust. I have read somewhere that switching off the camera first is a must to reduce this effect, but I am not that methodical, it seems.
My first attempt in cleaning the sensor was with Green Clean. Nice toolkit and cleaning was fast and effective. However the kit costs ~65 euro so it's not really affordable.
Once I got the knack of it, it experimented with Chicco cotton swabs and alcohol. It works pretty well, as well as the Green Clean kit, so I will not buy a new one or consumables for it.
The method is as follows:
Step 1. Use the suction cleaning to remove any heavy and large material (dust, fibers, etc).
Step 2. Use one end of the cotton swab with plenty of alcohol (wet not dripping) to perform the first step. Make sure that all the area of the sensor glass is wiped (all of the glass becomes wet).
Step 3. Before it has the time to get dry, gently wipe the glass with the other end of the swab (dry one) to remove the alcohol and stains.
Step 4. Use the suction cleaning once more to remove any stray dry material that may remain.
The only really useful thing in the Green clean kit is the compressed air can with plastic hoses and a suction tube that utilises the compressed air to create an ultra clean suction cleaner. Thankfully, I can get compressed air cans that are compatible with the kit's parafernalia at a modellist shop for ~ $5.
Therefore, my recommendation is to buy such a kit, get to understand how to clean and then utilise cotton swabs and alcohol. The suction clean is particularly useful to clean the pentamirror compartment that tends to accumulate fibers from time to time.
Finally, never use compressed air to spray into the camera compartment. It will just push dust and fibers to where they cannot be reached but will come out eventually requiring a new clean. Also, don't fear that cleaning will damage the sensor. It is well protected behind the infrared filter glass. Just to get an idea of how well protected they are, pay a visit to
http://www.lifepixel.com/IR.htm
This company's business is to remove the protective IR glass and replace it with plain glass (to make the cameras shoot Infrared). Take a look at several camera removal procedures. They are entertaining and show clearly that when we are cleaning the "sensor" we are merely cleaning a piece of glass.
however, care should be taken in case we have been at the beach or where there is sand. Sand contains quartz and quartz is harder than glass. We must not press hard the cotton swab against the glass (we don't need to anyway) and before the cleaning, a suction cleaning ensures that hard and heavy particles are removed. Then the cotton swab with alcohol removes stains.