Yep, heat & Kroil pretty much always works (well CRC or KW Knock'er Loose now that Kroil costs so damn much). And I don't even have an acetylene torch (not that machine tools need it), I just use a TS8000 with propane or MAP-P. Except I no longer use freeze spray anymore. I just used canned air upside down. Works just as well for me, much cheaper & easier to get locally. Luckily I don't have to deal with real rust when working on cars which doesn't exist here.