For his spooking problems, I'd suggest just working AROUND him with his combs, brushes, blankets... Hell, plastic sacks even. Just show him that they are there, but that they are NOT out to hurt him. Once he accepts the presence of random items you may be carrying around, get closer. This might take a while, but just inch closer day by day or session by session if you mess with him more than once a day. Set a comb near him, let him sniff it out and figure out that it's not going to get him. Eventually you should be able to work more safely around him. I know it's not your everyday desensitizing activity-- it's less direct and time-consuming, but if he's really as flighty around items you hold as you say he is, typical desensitizing methods could prove dangerous for both you and your horse.