Q-tips will leave its fibers all over the place, as will a tissue.
You're better off using a good paper towel or, even better, a coffee filter.
my cpu cooler is brand new, its just that thee sticker at the bottom came off when i was placing the cooler back in its plastic tray. do the plastic tray, so now i want to clean it
I have used qtips and toilet paper both with no issues. Just do a good visual inspection to make sure nothing got left behind. Coffee filters work great as well.