I took this shot to show what the sensor of my 30D looked like after 9 hours on one of those buses they use to shuttle you through Denali National Park. This was taken after I got the loose stuff off with a rocket blower. What a mess.
Sometimes the blowers push it further in behind the sensor, As my 20D did, the quote from canon was aprox AU $450.00 Hope you managed to get it cleaned OK!