I agree with Seb, I've wet cleaned my 5d2 a number of times. The first I nearly had a nervous breakdown but I just get on with it now.
I get my kit from
http://www.cameraclean.co.uk/products.php?cat=Sensor+Cleaning+Tools+-+Wet
I use their own blue pads at the bottom of the page, they are better put together than eclipse ones.
DON'T use a Brillo pad I got a lovely shine on my sensor but the photos arn't so good now .

DON'T use a Brillo pad I got a lovely shine on my sensor but the photos arn't so good now .