Here's some good info: https://homeguides.sfgate.com/clean-exterior-shutters-22990.html
If they are interior shutters, I would use a vacuum first to remove all dust and then go over them with a damp rag.
Hi Jean, so much depends upon your shutters. Are they inside or outside, slated or plain surface, wood or metal, etc. Here's some general information about cleaning all types of window accessories. Hope you find it of some help to you.