I've tried sulfuric (80%), nitric (70%), acetic (glacial), phosphoric (80%), HCl (33%), even hydrogen peroxide (25%) with zero results
I went the Scotchbrite™ route
Please enter a valid email to subscribe
We need to confirm your email address.
To complete the subscription, please click the link in the
email we just sent you.
Thank you for subscribing!
via Egeo 16