I had leaks with the dental floss method. Now I tighten an ALL-STAINLESS (screw included) hose clamp to the popoff valve housing and hang the little bag from that. I soak in starsan and wring out, and add four or five large Stainless bolts to make sure the little bag doesn't float off its hanger. After 7 days (or whatever) dump the overpressure and carefully swap the lid for a new one, then back on the gas. Done. I still find a few ounces of green sludge in the first pour, but that's it.