Well just make sure you don't inject that little floater. BTW: This seems to just be the luck of the draw in a manner of apeaking. I always used 23g pins and still got those floaters.
i use an 18" guage to pierce the bottle and use the same hole for three or four injects. i wipe the stopper with alcohol each time. after the fourth time or so i replace the stopper with a fresh one, which can be purchased cheap from getpinz.com. i have not had any problems with rubber flakes in my precious test.