I think he means fingerprint marks not dust.
are you reffering to the dust on the heatsink ?
yes for top and no, the fingerprint marks on the heatsink that I made during installation....
Ok if fingerprints, it won't really affect performance, only aesthetics. If its really bothering you use the 99% isopropyl alcohol on a cotton bud and rub it on. You may even be able to use the dry cotton bud as it is and it might remove them.