Briliiant, so simple and efective! I don't think I'll clean my road bike chain in a diferent manner ever again! Thank you for the idea!!
Not sure how it might work on the MTB, but will definitelly try it.

For the OP, if you're going through dusty roads/path, remember that "dry" lube atracts a lot less dirt. I you use a chain lenght checker, you can start looking for a new chain once it reachs 0.5 elongation, and change the chain once it gets to 0.07.

Worst case scenario, if you start off with a new chain, think you will wear it out, and fear you won't be able to find a new one... there are light chains which you could can carry as spare from the start of your travel, or get from the last "civilized" place you visit before going into the "wilderness"...

Good luck