I believe you because I have the same problem (see also post a couple pages ago). Everyone is really over thinking this. It's static electricity because it is electricity at rest - i.e. it is static. Static electricity will build up on any insulator, including Delrin which is just a trade mark for a particular type of plastic that is particularly dense and machines well. Since it's on an insulator it will not go anywhere until you take the effort to bleed it off. The table is already earthed (but probably only the motor), signal cables should only be connected to the cartridge, and the ground wire probably only connects to the arm. Nothing grounds the platter - nothing can, it's an insulator. Many years ago I used to do ESD sweeps of a factory floor that used some very sensitive devices, and I can say from experience the darnedest things will build up a charge if there is no where it can go. If I still had access to that equipment I could measure how much of a charge is being created.
I've been doing this for the past 2-3 weeks and it has been working well. Get a ground strap for your carbon fiber brush and ground that to earth ground (the big round plug in a US outlet). Don't have a carbon fiber brush? You should, so get one. They're cheap and quite effective at wiping dust, lint, and bits of fluff off before playback. I found a strap and ground plug on Amazon for about $10. The carbon makes the brush conductive, so if you ground the brush any surface charge it sweeps across will go where it needs to go and be neutralized. Clean the record as usual before playing, it will not have static on it when done. When I notice static building on the platter, brush off the platter (which is probably not a bad idea anyway). Quick, easy, and effective.
Eventually I will mod this to tap into a nub on the handle that is specifically intended for grounding (on the right). Good luck!
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