When I'm touring, I have this nagging thought...
When I get to the airport to ship my bike back, I won't be able to get the pedals off, as they're on too tight (they self tighten when riding). It has happened..almost.. before, and almost missed the flight (international!).
So... I'm thinking of putting a small thinnish rubber washer on the pedal, so that it could just be seen between the crank and the pedal axle when it's fully tightened.
Am I stupid, is this safe, will it work, is there a better way.
BTW, I travel with a pretty good pedal wrench, and I still have problems.
I would not do this. If the crank thread wears out, it's dead. And it would be painful if a pedal should fail. I remove my seatpost and use it as leverage on the end of a cut-down pedal wrench. No problems so far.
Anything that prevents the pedals from being tight will result in stripped crank threads. The best bet is to use a good layer of grease on the threads. Consider using your pedal wrench once a week or so to break each pedal loose and retighten during your trip. Or, the day before you need to break down the bike, stop at an LBS or auto shop and ask the mechanic to break them loose for you.
As an alternate, you could get a set of MKS quick release pedals (Harris Cyclery has them). You'll need to use clips and straps or PowerGrips with them, but they go on and off like a quick release air hose fitting.
If you go to your local automotive shop and buy some anti-sieze compound your problems will be over. The stuff I have been using for years is silver in color, seems to work much better than grease. It works so well that I use a little cone wrench to remove the pedals at the airport, or an allen wrench depending on the pedal.