Artificial intelligent assistant

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.

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