^^^What he said, and yes, I have used a 5/32" bit one several plugs over the years. Try to hand turn the bit at first, or you can put drill bit in a set of pliers or a vise and turn the plug, or you can precisely use an electric drill (what I do). For one's with a lot of carbon, you can soak overnight in a cleaning solution and then drill them out. Also, when using a drill, install an old vent liner to protect the threads.