Thanks Brad and Brent for some good ideas. I guess mechanical is the way to go - I can access the right sort of grinding sludge. Brad - if you managed that, I take my hat off to you! Cheers all, Andy Brent Garber wrote: > Andy, > I can't say I have done this before, but you may find Di : H2O2 : H3PO4 > (1:4:3) will work for you @ 38 degrees. > I do it mechanically as I can't have anything happen to my front side. > Brent