I tried working with Chrome on backing away from his hay but he didn't generalize it at ALL! When he's in his stall and I'm feeding him he will back all the way to the fence, but when we're in the open side of the barn (Zep's stall) in front of the hay he just didn't get it at all. It's like he completely forgot how to back on. To be fair we really didn't work on backing all that much I don't think. I really need to work on backing some more with the clicker so he's working for a reward instead of being kept away from something he wants (the hay). He's still doing great in his stall for dinner though. He backs all the way to the fence and has even started to pause.
I also worked with him with the umbrella (but no clicker or treats). I wasn't as patient or thorough as I should have been but it was freezing cold and snowing. I guess what I learned from the whole thing is that clicker training sure makes desensitizing so much easier and a lot more fun for Chrome. I messed with him until I could touch him all over with the umbrella closed, swing it around his head closed, swing it in front of him open, hold it over his head open and touch his back with it open. I think with clicker we could have been a lot more thorough and he would have been a lot more relaxed, but for a quick session I think he did really good. You can see pictures and read more about it on my main blog here.