Homebrew PCBs

If I add 3% H2O2 to regenerate my etchant, I'm adding a lot of 
water to the mix, so I'm wondering if there's any advantage or 
disadvantage in bubbling oxygen rather than air through CuCl2 etching 
solution? Or does the air itself regenerate the solutionadequately in 
addition to agitating it?

Mark