Popa, I didn’t say you showed your amaratzus by not looking up the Shach, just by not looking up the Mishna Berurah.
There are two issues here. The OP wanted to know if you can eat pareve cooked on a dirty fleishig grill during the nine days. I think the source for that is ???”? in ??”?, and ?”? in ??”? doesn’t seem to me to be relevant, as the two gezeiros are for different reasons. It’s possible that ???? ????? ???????, but that’s conjecture until I see a source.
The thread title makes it seem as if it has to do with “being fleishig”, IOW, ????? ?? ????, which leads to the discussion on the ?”?. I think it’s pretty clear that he’s talking about where some cleaning was done, I also don’t think it would necessarily be nogeia in a case where there will be ???? on the food. There are also a few ??????? who argue on the ?”?.
See ‘?? ????? ?”? ?, especially second wide line.
http://hebrewbooks.org/pdfpager.aspx?req=15008&st=&pgnum=323