What are you worried about? They catch that one very easily when they swab. I know of a lady who got stopped from traveling because her sister loaned her a bag and the sister works in a fireworks factory. Tests for nitroglycerine and products are, I thought, very very sensitive if not oversensitive -- urban legend has them giving false positives to ladies who use hand lotions that contain glycerin.

By the way my story has a happy ending, as the lady traveled after 911 but a couple of years before 8/10 -- they did search all of her bags but after questioning they determined that the problem was undoubtedly caused by her contact with her sister and the sister's bag and they did allow her to fly.