I think a previous boss of mine had the best idea by making any touching of the dials and screens a hanging offence. Boeing actually issues screen cleaning packs consisting of a paper tissue impregnated with a cleaner and a dry tissue to wipe it off, made in Devon or Cornwall, UK - get your engineering stores to order a load.
I use these packs whenever I can get hold of them but I draw the line at one colleague's practice of carrying a miniature dustpan and brush in his nav bag!