If you are anal about the look of you chasis and other metals, You might want to draw back in fear of Exacto knifes. A stiff cleaning brush or dental pick works wonders, speccially for tight hard-to-reach places. as for the screws throw some threadlock and a small washer, one with a very think height, And it will keep most of the crud out of the sink- and allow you to clean it a lot easier. I have also heard that washers will keep the vibration down. As for metal or plastic washers, I use plastic.