I just went to California last month and my carryon and purse were scanned many times - my applique kit contained two small scissors and a seam ripper and nobody gave it a second look. (But, I was selected for secondary screenings a few times - I guess I look like the type who might have explosives residue on her hands. ;) )
You could also carry a dental floss container - it has a built-in floss cutter. :)