Extracting DNA from a kiwi
Yes, a full kiwi. The method is rather crude and the yield you get is not so high, because you will not break up all cells and also loose some of the DNA which is bound to the cell debris.

Lab filter paper of course works as well, as would a fine cloth (cheese cloth for example). The receipe is designed to work with stuff that people have usually in their kitchen, which is true for coffee filters, but usually not for laboratory filter paper ;-)