This is a old post but thought I'd chime in with what I did this weekend. My
oil & water temp gauges came with the 5/8" unf blue anodized sets inside a 1/2" NPT adapter. I didn't care for the blue so I used Easy Off to remove the blue. Before I brushed on the cleaner, I taped off the capillary to prevent any damage. The cleaner works really fast so don't make sure not to leave it on more than 30 seconds. As you can see, The upper fitting looked good after the first application but needed a second pass to clean the threads. The lower fitting is the "before" treatment. Overall I'm very pleased with the oven cleaner and glad I didn't have to go to the back-up plan of using steel wool.