The idea of a ground plane for the chairs isn't a bad though, but it wasn't executed in the best manner possible.
First off, it would work better if, rather than a wire along the carpet, it was a grid (screen) or plate (copper foil) under the carpet in the affected area. Then, the carpet needs to be treated to improve its conductivity. Static guard spray (as mentioned by Mr. Swaffer) is basically fabric softener in a spray bottle. Fabric softener works by hydrating the fibers so they are more conductive, and lubricating the fibers so they are less likely to build a charge as they rub against each other. You may need to shampoo the carpet more frequently as the static guard can build up and trap dirt. (If you think about it, synthetic carpet fibers are basically plastic, and plastic is an insulator or dielectric. As you move across the carpet, your shoes strip electrons from the dielectric -- or maybe the electrons go the other way -- so you end up with an imbalance, or charge, between yourself and other objects.)
Secondly, this grounding needs to be bonded to the grounding system of the building. That helps to ensure that the voltage potential of that grounded area is the same
as the voltage potential of the grounding of the sound system.
On the other hand, just using the static spray might be enough and no complicated grounding system would be necessary.
You might also recommend that your church have their HVAC contractor install equipment to help maintain the humidity in the building. Ideally, indoor humidity should be between 40% and 50% RH. Besides reducing static charging, proper humidity also prevents warping and cracking of wood furnishings and trim. If you have a pipe organ or piano, maintaining steady temperature and humidity is key to keeping those instruments in tune.I am not an electrical engineer, but I play one on the Internet.
P.S. -- Thank you for reading the rules and using your full real name on your first post!