Can't think of anything off hand. you could try Simple Linctus (basically cough medicine without the active ingredients) as you don't need the anti-cough stuff, you just need to treat the dry throat.
The best treatment would be to humidify the air you are getting but that is rather tricky as far as I can tell. The only ways we have of humidifying gases in hospitals involve masks and ultrasonic nebulisers or hot water baths so unless you want something akin to an arab Hookah to breathe through you might be a but stuck. Will ponder the problem and get back to you if I have any brainwaves!