I would be happy to use them on everything on a projector OTHER than the lens of the projector. Generally you should avoid cleaning the lens at all if possible. But, a very light dusting off with a microfiber cloth is the way to go.
You can use a lens cleaning cloth and a small bit of lens cleaning solution if you absolutely must...
www.nikonimgsupport.com
But, be aware that Nikon only has glass lenses. Some projectors have plastic lenses in them, so you want to be extremely careful around the lens. I personally never clean my lenses. Dust on the surface of a lens will not impact performance, while damaging a lens could destroy the entire projector.
