Half a tablespoon of EDTA plus one tablespoon of sodium sufite clears more effectively than plain EDTA, at least with some papers. Another very effective approach is to use a first bath of citric acid, one tblsp per liter, followed by EDTA or EDTA/sulfite.
Jorge, depends on the paper and probably the water supply. I've found permawash does great with some papers and either fails to clear a masked test area on other papers, or, more difficult to spot, leaves an overall stain on the entire sheet compared to an unprocessed sheet. Always test with some of the coated area masked off, and then additionally compare the finished print to an unprocessed sheet of the same paper to find any overall stain.
Thanks fot the tip Carl. Since I dont like the alt border look I mask my neg with rubylith and get an automatic check for clearing. the 3 papers I have used all cleared within the first bath. Still put them in the other two just in case, but so far PW has been wonderful.