01-12-11, 12:08 AM
No need to worry about swarf from the tap, IMHO. The vast majority will come out on the grease on the tap. In the unlikely event that any stays at the bottom of the spigot, it will get burned up and blasted out the headers when you start up. 
If it bothers you still, clean out the spigots with a cotton bud after cutting the threads.

If it bothers you still, clean out the spigots with a cotton bud after cutting the threads.