I've sprayed a bit of silicone lube on the cleats, at the pedal contact points to make the squeak go away. Silicone is a dry lube and doesn't attract dirt. It's a light lube and the problem is it is only a temporary fix and needs to be applied every now and then. It drives me crazy too, and notice it most on hills. It's one of those annoyances that could be solved just by turning the radio up a little louder (if it were a car).