de-esser: good idea - will try the logic one
multiband limiter: also good idea. I'll try logic's Multipressor, and it's possible that the Sonalksis DQ1 might do it, but I have no idea how to work it atm.
edit them out by hand: not a good idea in this case - the squeak here is an artefact of 'legato' playing and covers chordal content. I tried it, though
duplicate track idea: this would be the same as manual reducing the volume precisely around each squeak, which I've tried, but it messes with the chordal content.
For a minute there, I though you were going to suggest phase-reversing the duplicate squeak! ;-) ( which would also effect the chordal content)
really good ideas, Alan, and solid stuff to work on. I'll let you know how it goes
what I've done meanwhile is to EQ down the guitar where it is isolated ( which is where the squeak is really annoying) and when the track fills out and the guitar strums, I've EQ'd back the high mid, where it sounds best.
peter