Interesting that you say that the level of humidity is the cause. In fact, it's only at home that I DON'T get zapped, because we have a humidifier! In public places, like malls, it's bad. That's where the locker is that I referred to, in the gym. The air is very dry there. However, I'll try the key trick today, and see how it works.
As Claude says, cotton clothes are out of the question in winter - it's all heavy wool/synthetic mixes for below zero temperatures, and rubber soled boots.