I just went back and looked at the first page of this thread. I didn't realize you used a washer as well. I thought you found a switch that perfectly fit into the hole.
Basically i completely copied you. And if somebody didn't want to use the rubber gasket, you could just wrap a ton of electrical tape around the barrel of the switch until its just a bit tight.
This setup is super slick though and I love the factory look. Even if you don't have a civic, you can use the civic shifter mod on your car with similar results.