With a blower you might force dust into the compartments of the speakers possibly reducing sound quality. I've used a vacuum with one of those "brushes/bristles" add-on at the tip of the vacuum to clean the speakers easily.
If your vacuum is very strong you could even attach a sock/nylon at the end of the bristles to reduce the suction.
Static can easily be circumvented by grounding yourself while you clean the speakers, and to not clean them on a carpet or move around too much when cleaning them.
Just always make sure to unplug the speakers from the wall or any electronics when doing so.