I think it’s pretty common knowledge by now about the TF2 idling program.

Just login to Steam, run the program and you’ll be unlocking all of the items over time. Mind you, the challenges to earn them has been lowered so this is more realistic now but at least this gives you a low impact way to do it as well while doing other things. Read the forum post before using it and any hats you earn, save them to send to me once they implement trading!