To prevent it from happening again:
Use some kind of no-heat forced air boot dryer after every single ski day. No exceptions. Don't leave them in the trunk of the car or under the basement stairs.
Never re-use a pair of socks. Clean socks every day. Don't let them touch the floor of the lodge, locker room, or condo.
If Salomon says to wash 'em, go ahead (as you already have). My liners are full leather lace-up (hmmm...sounds kinky
) custom foam things. They will never, ever go into the washer or the dryer.
Ski boots can't possibly be as bad as neoprene kayak booties. Neoprene is notorious for developing all kinds of wonderful, um, "atmosphere."