If the pads the printhead parks on are saturated, the air line for the vacune pump could be clogged. I've never dug that far into a 2200. www.fixyourownprinter.com
has some tips and ,IIRC downloadable service manuals, which may give you some idea of whether it is fixable, or its time for a 2400.
They also sell a waterbased ink solvent they report is the same stuff Epson techs use. The stuff has solved some nasty clogs for me. Alcohol is a no no. You may be able to soak the pads and attempt a head cleaning to draw the ink solvent thuu the vacume line, if it is clogged. The ink from the cleaning is deposited in the internal pad mentioned above. The pad may also have a "plug" of dried ink where the vacume hose terminates so the solvent , if it can be drawn down this hose, may also be able to dissolve this. This process should also dissolve the dust and ink you alluded to in your post.
This is purly conjecture on my part. As I said, I haven't gone this deep into one of these printers. Hopefully it gives you some ideas on how to procced.
Also, I think www.inkjetart.com
had a step by step dissection (with photos) of a 12xx series epson. It was quite enlightening. Especially about the small vacume pump that draws ink out of the printhead during cleaning as I also mentioned.