Vincent, you could try the most likely answer and soak the reels in hand-hot water for half an hour then scrub out the tracks with a nail brush. After that, a few hours in a bleach-and-water solution will have them very clean.
The next main thing is having them dry of course, so if you find your hands are getting sticky (not unreasonable inside a changing-bag in Singapore) you could use a pair of those latex or nitrile examination gloves. Your hands will certainly be sticky, but the gloves should reduce the dampness in the bag.
As a last failsafe, put a couple of light-tight plastic bags (maybe the ones from 5x7 paper) inside the changing bag so that you can secure your film out of harms way if you have to open the changing-bag before the film is in the dev-tank.