Diluted Evaporust will not be effective. But you can soak an entire frame and fork in 1 1/2 gallons of Evaporust by using the "waterbed" technique (see http://www.bikeforums.net/classic-vi...evaporust.html). The Gitane TdF frame I treated that way came out clean as a whistle. It's easier and safer than oxalic acid. Since you have to buy two gallons of Evaporust it will cost $40 or so, but the results are worth it. You can re-use the Evaporust multiple times, so it gets cheaper if you do a few frames.

Not trying to knock oxalic acid--many around here use it. But I no longer do, mostly because it's very damaging to aluminum and I like not worrying about parts that combine both steel and aluminum.