They mechanically come out of adjustment? That's a new one on me, and I don't see how it's possible. When I go through deep water I'll lose my drum brakes for a while due to all the water in there preventing the pads from doing their thing to the drum. But once it dries out, the brakes are back to normal.

If the brakes are coming mechanically out of adjustment your pedal action should be different. You don't mention that. Are you really sure they are mechanically coming out of adjustment?

'97 T-100 SR5
'86 Toyota's, the variety pack (all gone)