"... would you hand wash Filson's or other whipcord wool pants?"

Yes, I would. Even if they were mine. :grin

IMHO, I don't see a great diffeence between warm and cold water. Fill your washer with warm water and stick your hand in it. Tepid, is more like it. Close enough to cold that it probably doesn't matter.

Just remember that there is also a product called 'wool felt'. It is created by heat and friction. You don't want to do that with your clothes or good blankets. Cool and slow is what you want.

I usually use a short 'gentle' wash for woolens just to swish any soil and body oil out of the fibers, and it has always turned out well. I received a queen-sized, primo wool blanket as a gift several years ago, and it is still light, soft and fluffy.

The blanket that my stubborn sister washed on a long cycle and dried for 40 minutes on (probably) med-high or high, is a hard, stiff, itchy mess, like wool felt cardboard. She is not allowed to wash anything of mine that even resembles wool. EVER AGAIN.

Sue