I bought cleat covers for my cleats that go with my Speedplays.
They were absolutely USELESS! All they did was fall off. So, I returned them.
Then the next cycling rally I went to... I took plastic grocery bags and tied them around my feet when I had to walk in mud.
Mud in Speedplay cleats is a KILLER... basically you will never get the mud out until you can get to clean them in a sink... and then you can't clip in.
So, even though I looked silly and people laughed at me... I didn't care... cause my cleats were clean after every rest stop!
"Life is not a journey to the grave with the intention of arriving safely in a pretty and well preserved body, but rather, to skid in broadside thoroughly used-up, totally worn out, and loudly proclaiming: WOW WHAT A RIDE!!!!"