With mildew I'd be inclined to use a two stage process. I'd start off with a manual wash using the Knosti Disco Antistat washer (available www.audiophilecandy.com and other places £45). I'd use a solution of 35-40% isopropyl alcohol (not for shellac records though), with rest purified water and a few drops of wetting agent (Ilford for instance) per liter. The Disco antistat has a good scrubbing action, which is what you want. Pass the mildewed record through the brushes several times. Then vacuum on a convential vacuum machine, and repeat the process but don't use the Disco Antistat - instead use your favourite cleaner -- Disc Doctor, Art du Son, whatever. Change solution in Antistat every few mildewed records. If you don't have a vacuum washer, then use the Antistat twice, but change liquids between washes. The result will not be as good, but may be acceptable.