Rescuing bedding that already smells
Start with air, because it is free. On a dry, breezy day — cold is fine, cold and dry is ideal — hang the duvet or blanket outside over a line or a balcony rail for several hours, turning it once. Sunlight helps, but moving air does most of the work. Indoors, a clothes airer in a room with the window cracked and a fan pointed at it will get you most of the way in a day.
If airing isn't enough, wash what can be washed, using less detergent than you think and adding a cup of white vinegar to the rinse to strip residue. The crucial part is the drying: a duvet must be dried right through to the core, which usually means a long tumble on low with a couple of dryer balls, then a further day draped over something airy. A duvet that feels dry on the outside and cool and heavy in the middle is not dry.
For things that can't be washed — a wool blanket, a heavy quilt — lay it flat, sift bicarbonate of soda generously over the surface, leave it for several hours or overnight, then vacuum thoroughly with the upholstery attachment and air it afterwards.
Storing so it doesn't happen again
Everything goes away clean and completely dry. Then choose breathable containers: cotton storage bags, old pillowcases, a zipped duvet cover with the bedding folded inside it, or a lidded basket. Natural fibres in particular need to breathe. If you must use plastic boxes for dust protection, don't seal them airtight and don't push them against a cold wall.
Leave space between stacks so air can move, and keep a moisture absorber or a bowl of bicarbonate of soda on a shelf in a cupboard you know runs damp. Dried lavender, cedar rings or a bar of soap tucked between folds add scent and, in cedar's case, some deterrent for moths — refresh cedar by sanding it lightly once a year, because once it stops smelling it stops working.
