I was an early adopter of the original Zerostat (I’ve had models with white, red, and blue plastic bodies), and suffered with it’s idiosyncracies for years (the pistol needs to be squeezed and released verrrrry slowly. Irritating!).
It was a relief when the Kilavolt No.103 by Nagaoka was introduced, as it is operated with a simple on/off button (3-5 seconds is all it takes). By the way @lewm, the Kilavolt emits only positive ions. Also worth noting is that for maximum effectiveness, Nagaoka advises "spraying" the LP with the disc held in one’s free hand, rather than on the turntable platter. One YouTube hi-fi reviewer (I don’t remember his name, but he is bald, bearded, and tattooed) verified that claim in his review of the Destat III (which I also own. I waited to buy until I found one at a very reduced price).
Which brings me to the HumminGuru Orbit. It emits both positive and negative ions, and must be used with the LP on the platter. It therefore treats only the play side of the LP, rather than both sides. Handheld guns may be used on both sides of the LP, for instance immediately after cleaning and drying on a vacuum machine. As they say on The Shark Tank, for those reasons I won’t be adding an Orbit to my LP maintenance kit.
As for the Hudson "Antistatic" Arm/Brush, it may have some value as a dust remover on LP’s being played, but is obviously incapable of negating a static charge.
As the Kilavolt had been out of production for many years, the Destat III would be my first choice for static removal from LP’s. Too bad it’s price is so unattractive to many.