I use a simple soft dust wand to clean my speakers so no damage easy on the surfaces and takes the dust off. just don't press too hard. If you do it regularly there is no need to cleaners or water. The car cleaning industry has many very good dusting ideas to consider as they are designed to not scratch the painted surfaces of a car.
Best home remedy for paper cone woofers cleaning the dust off?
Whats the best way to clean them? Other than aerosol pressured cans. Also should you treat the rubber surrounds or let sleeping dogs lie?