I am not so sure that there is really much difference between rottenstone and whiting. After all, they are both essentially calcium. However, in my use I have noticed that whiting appears to clean slightly better, but at the same time its residues (being white) are more noticeable. I actually had more problems with fogging when I was using rottenstone.

Just a thought: It would be a lot of fun someday to hold a wet-plate conference/get together. The CW crowd have their "jamboree" every year at John Coffer's place way out in Dundee, NY (and I am sure we would be welcomed), but I often feel that our (if I can lump us all together) or at least my non-technical needs are often quite different. Perhaps I should post idea on Quinn's site.