2 hours? Eesh...You can get so-called 'flap sanders', which are like little drums with bits of sandpaper sticking out. They won't reshape things, but they will clean stuff up quite quickly. Other than that, I'm liable to just us a sanding pad (shaped, or stiff foam), and good quality paper, nothing coarser than 120. 60 and 80 grit scratches are hell to get out of end-grain. For the rest, I use my orbital sander. Finish sanding the whole guitar, with quite a bit of hand-work, should take max 2 hours. Unless you're oiling/going a lot finer than 220/320.
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