one more important thing: i'm not an hygienie maniac but it's better to use the scroll with extremely clean hands... i'm not a doctor but i think that the dirty inside my mouse is my dead skin with dust... so always clean hands and if you can cover the mouse when not in use...

if you clean it on the white paper you have a good result the first time but you will damage it doing it several times... my old mighty mouse doesn't work because the scrolling ball has damaged a little piece of plastic inside the mouse. my second mouse works perfectly since 2008 because every 5/6 months i open it and clean the internal parts just with my fingers, without alcohol or other stuffs... every time i need to break the lower side with a cutter but i always fix it with glue when i finish to clean...