I'd be surprised to some degree if Optimum made Griot's RW. I asked Griot's a few years ago about this and they said their benchmark was ONR but it was formulated by them. Griot's likes to formulate in-house.
I don't like RW'ing all that much but when I do I use multiple towels so dirt dropping isn't a problem.
I don't like RW'ing all that much but when I do I use multiple towels so dirt dropping isn't a problem.