I took drastic measures with two of my wool sweaters. One is my Rogue, and the other is my Mariah that I just finished. Rogue has always been about 10 sizes too big, and I never wear it because it is too sloppy and huge, even though the knitting and assembly parts did turn out very well. Mariah suffered a similar fate - I wore it this weekend, and it is at least a couple sizes too big, and the sleeves were way too long.
So, I crossed my fingers and tossed them into the washing machine, set to a regular load at medium temperature. My washer is a front loader, and I'm pleased to say that no actual felting took place. However, I do believe there was some shrinkage, which was exactly what I was looking for! I'll know tonight for sure - they are drying on the bed in the guest bedroom. If it works, I'll have to try the same thing with my Lace Leaf Pullover - that thing has expanded to ridiculous proportions. It has moved beyond comfortable and into clownish territory.
Incidentally, my washer has an awesome "Handwash" cycle that works great for all the handknits that I don't want to shrink. It saves me water, work and drying time :)
I'm taking a break from sweaters and working on my Lenore socks. I always forget how much I love Blue Moon yarn until I start using it again. And the pattern is fun. I just turned the heel on the first sock last night, so I am making pretty good progress.