I have really sweaty feet and as a result every time I go skiing I soak my ski boot liners. And even though I have a ski boot dryer that I use pretty religiously my ski boots still stink. I’ve tried a bunch of things to clean em but the only thing that has got the stink out is McNett MiraZyme Enzyme-Based Odor Eliminator. I poured two cap fulls in a partially full tub, submerged my liners for ten minutes, dried them outside and viola! No more stinky ski boots.
I’ve also used it on my backpack which got a little smelly too with great success.