How to clean out the inside threads of a braze-on? I'm installing a basket on my cruiser, and getting some of the allen screws into the fork braze-ons is rough going. It feels like there's dirt or grease inside the threads of the braze-ons. Forcing the screws in could damage the threads. 

How can I clean out the inside threads thoroughly, using common household items? 

Note: Folks installing racks and fenders will often run into the same problems. I mention it here so searches on those terms will show this question.)
I use Q-tips and a degreaser (WD40 or similar will work).  Spray on, wipe off.  Soaking helps cut hard to remove grime.