After putting back the plugs on the block and transmission from winterization I noticed they were heavily crusted with rust and had a hard time threading them back in. I was able to clean them enough to get the plugs back in but they don't go in very deep and didn't want to reef on them hard in case they were going to ruin the threads.

What do you guys do to clean the threads? Do you use an SAE tap and re tap them carefully to clean out the rust etc?