
Fastest safe fix: hang the jacket on a sturdy hanger, turn it inside out, and lightly mist it with a 50/50 mix of cheap vodka and water or a 1:3 white vinegar to water mix. Do a quick patch test inside the hem first, then use a very fine mist from about 12 inches away so you dampen, not wet, both the lining and the underarm/collar areas. Follow with a garment steamer held 2–3 inches away, moving continuously so you warm the fibers without dripping; a few slow passes inside and out helps release musty compounds. Hang it in strong airflow for a couple of hours, ideally near an open window with a fan on it; 15–20 minutes of indirect sun can speed things up, but avoid prolonged direct sun on wool. In most cases the smell drops dramatically within 2–4 hours with this combo.
No steamer? Hang it in a steamy bathroom for 10 minutes, then move it to a fan to dry, and use an unscented fabric refresher if you have one. If a trace of odor lingers, park the jacket on a hanger in a breathable garment bag or a large bin with an open bowl of baking soda or activated charcoal nearby for a few hours while air circulates. Avoid soaking, washing, or any heat cycle in the dryer; agitation and heat are what shrink wool and can water-spot acetate or rayon linings. Brush the exterior with a clothes brush after drying to lift the nap and finish freshening the fabric.