object-preview cheat not working

Hi - I'm trying to update my cc beds using a tutorial posted by Peacemaker. He references the object-preview cheat, but when I try to type it in the cheat popup, it doesn't work. I searched using the 'help' cheat, but it doesn't show up in that list. I'm using the newest Mac beta, 1.3.4.0 (apple blossom). 

Any suggestions? I've played with S4S in the past, but this is the first time I've tried anything harder than a recolor. 

Thanks!