The "active" ingredient in Oxyclean is H2O2 (hydrogen peroxide). That would help a great deal. The stuff you get in a pharmacy is about 3%. You can concentrate it by boiling some away but be careful. Higher concentrations can be hazardous (30%) to deadly (> 60% can literally burn your flesh away). I use 30% frequently for fabric cleaning and it will burn the crap out of you in a millisecond! It winds up diluted to about 5% by the time it sees the fabric, heat (135-165F) and a touch of ammonia will make it more aggressive. Of course you may well wind up with a "bottle blonde" brush!