Marbles for medium!

Good afternoon RIU people! Has anyone ever used marbles or glass gems as a substitute for expanded clay medium? I would think that they would work fine. Should actually be easier to clean since there aren't any cracks in the glass. The only negative i can think of is that the marbles may reflect light onto the roots. I would go and buy more expanded clay but my nearest shop is abt 3 hrs. Stay thirsty my friends. Peace!

I've found that marbles work for a quick fix but they're kinda hard to deal with. Tend to move the clone about when filling the cup.