Number 1, I think Jack is talking more about an applicator brush to be used during the wet cleaning with and RCM as opposed to a brush to simply sweep of surface dust in between cleanings.
Number 2, I know that the brush that Pete posted a picture of has a metal piece that says touch here for discharge, but keep in mind that touching that spot will do nothing unless you yourself have a good solid connection to ground. if you are standing there in a pair of rubber bottom sneakers and are not touching anything other than the brush there is no path to ground and no static drain off will occur. The Mapleshade brush on the other hand had a wired connection to ground to insure that the static will have a place to go regardless of how the brush is held. This by the way is not a new idea. I have a 30 year old brush put out by Oracle ttat has the same kind of ground wire.