Soap and close toe bindings

This Christmas, we got some Murray closed toe bindings. I was able to use them for the first time last weekend and the were very difficult to get in and out of. Seriously, it took me 5min of torqing and twisting to get into the bindings (this all happened without the use of soap). I was wondering if I could use soap to help me get into the bindings? Previously I thought that I couldn't because the soap would ruin the neopreme, but now I reconsidering this notion. What soap do you recommend if infact I can use soap? (FYI the bindings are XL and I have size 12 feet)