How do you folks keep your SAKs clean after toating them for a long time? I know mine gets so full of lint and dust that it's rediculous. I've tried blowing it out with compressed air, running q-tips through it, but it always still seems dirty. Also, have you ever noticed that grayish-looking film that forms on the red handles? I usually just wet my finger and rub it off, but I was wondering what causes it. No matter how dirty it gets, my SAK still get the job done every time I've used it. Thanks