How do you clean a dollar bill?

i have a dollar bill thats real special to me, its got sentimental value from a personal experience i had a few years ago. Its gotten kinda grungy and dirty and has some weird stains from i don't know what, and i was wondering if there was any way to clean it, you know just the dirt and the stain, not wipe it for counterfeiting. I'd appreciate any help, i would like to hang up the dollar in my office and i dont want it looking dirty.