I don't know that H2O2 reduces Fe(III). (It does reduce Mn(IV) and (VII)
quite nicely however.)
Plain old base of any sort (sodium carbonate, oh and BTW Oxyclean isn't
sodium bicarbonate peroxyhydrate, it's carbonte peroxyhydrate, mislabeled as
percarbonate) will neutralize the acidity, producing -- what else -- rust.
Make a solution of base (alkali [bi]carbonate, hydroxide, etc.) and add to
the ferric chloride until the solution is clear (the solution, not the
precipitate!).
If you would like to reduce it first, toss in some cheap metal like iron
nails and stuff. You'll get brown crud and a green solution of Fe(II)
chloride. Then neutralize.
Or just flush it with a lot of water, iron ions don't last long in the
environment and a little acidity (diluted, that is!) never hurt anything.
Tim