My DH is more like that than I'm going to describe here. The only *big* difference is that he is starting to see the big picture consequences, and he just gave me permission to toss ANYTHING. So, that's not getting him to do it, but it will eventually get the job done. In the past, he has complained about stuff I was donating, even if it was from the kitchen, so this is a big change.
Like Kris (in the FLYLady thread), I have success pulling out stuff and leaving it on the bed for him to sort through. (Because it's hard for me to throw out his stuff if it isn't obvious trash). It has to be a small amount, but it can be several times per week. And it helps if I organize for him, so that at least his tools are in one place, and school stuff in one place, and hobby stuff in one place.
Counting DH's pants motivated him some, because he had no idea he had so many. He is now saying he needs to sort through them (which is far better than me saying he needs to do it) and it has stopped him from buying more. (My DH is a huge shopper. At least he's a bargain shopper)
In your case, if he has nice clothes he rarely wears, I'd ask him why. . . and consider donating them if he doesn't like the color, the style, or the fit. If he doesn't love it, and doesn't wear it, it's not worth keeping when someone else will love it. Maybe save a few outfits he likes for special occasions.
Jo
DD#1 "JellyBean" 6/08
DD#2 "Ha" 6/10
"Theory is great, but as I'm in the trenches of diapers and dishes and ear infections, I try to relax and focus on what's most important: love."--mjs64