Oh well, I've shoved worse things through the pipes in my body! 8) Last time looked clear to me... could just have filtered just enough to make it not visible.
In the past I would filter OC's using a 1cc fit packed with dental cottons to the 30 unit mark. First I would draw the solution through a dental cotton with a glass eye dropper, then I would backload the cotton packed syringe with this. I would then force the solution through the cotton and into the fit I was going to boot with by backloading it as well.
This filtering process would produce a visibly clear solution, yet it would still contain all the talc.
Just because you can't see it dosn't mean it isn't there!