Join Date: Sep 2004
Location: East Tennessee
Bikes: 2002 Lightspeed Classic; 2010 Pedalforce RS
What I did to make my speedplays more walkable, might work for you.
I got an old pair of flip flops. Look for ones with stiffer soles, not the cheap spongey things. These are light weight and good for walking. If you find some on sale, you might go for new ones. Cut out for the cleats and glue to the shoe with contact cement. Worked great for me.
To get 3/4 in thick you may need 2 layers.