@lewm
I am eager to try your method, since it would save time and extend the life of the Zerostat, since fewer shots per LP would be needed. The slow pulling away of the Zerostat from the LP in your method sounds like how one uses a demagnetizer to demagnetize tape heads. Since you have that meter, it would be interesting if you could compare the effectiveness of the two methods.
The method I’ve used involves keeping the gun 12" away from the LP, squeezing the trigger and releasing it for the first 3 shots, but not releasing it for the central shot until the gun is pointed away from the LP. I do not squeeze or release the trigger slowly as you describe--there usually is a click as I release it. I don’t try to squeeze it fast or slow, really, and I don’t think the speed was mentioned in the Zerostat instructions. I will see if I can find the original instructions; I may still have them.
I generally have done this with the LP on the turntable, and it works that way or if I hold the LP in my hand. But I don’t know if both sides get destaticized if it’s done with the LP on the turntable. I think the act of removing the LP adds a charge to the side that rested on the platter, so it would be hard to test if it works on both sides when the LP is on the platter.
If your method destaticizes both sides of the LP with one shot, it would be economical to destat the LP both before and after play. Unfortunately, even though I slit the LP sleeve, some static charge still develops from the act of removing the LP, although I think the side that’s down when I lift the LP gets more charge.