Shure did show and did publish data to show that when you discharge one surface of the LP, that charge can leak over to the side of the LP that is against the mat.
Hmm...when I use my Zerostat on one side of an LP, static is reduced on both sides. There is an increase in static after playing an LP side, as indicated by the attraction of a small piece of styrofoam taped to a piece of thread. I don't know if this is from the stylus friction or from my transmitting static to the LP; I'm thinking it only occurs after removing the LP from the TT, but I'm not sure of that.
After using the Zerostat before play, I hear no static, but the humidity in my home is about 50%.

