I seriously doubt they checked after they passed a wet swab over it.
they do it once wet then dry then send on with a bill
there are heaps of bunnies after most cleans unfortunately.
it took my 7 tries to get it good this time and about 15 last time.
I am a bit toooo! anal about cleaning and have worked a routine.
If you are serious get a can of liquid air (CO2) and a few swabs and say Gday ( I'll help the first time for a beer), purchase a rubber bellows ans you can then do it all on the run.
my Eos - M came with a few and so did the 70D with only 1031 shots on the count,
I have a friend that picked up his 5D MK2 sealed in the return box from "Canon Aus" and there was one huge and 3 small dust spots on the sensor
I assume the huge one fell on in transit and the 3 on the edge of the sensor were there when it left the service centre!
You should catch up oneday or I will send the "Iron Triangle Boys" after you! OR my Sister!
I want to stand as close to the edge as I can without going over. Out on the edge you see all the kinds of things you can't see from the center.