Does eucalyptus oil work inside your covers to get that old musty smel

Wipe out all your cupboards out with vinegar. I use fresh Bay leaves and lavender in my linen cabinets and bay leaves in my kitchen cabinets.

washing them with laundry soap is an idea

I would wipe them down with a 50/50 mix of vinegar and water with several drops of lemon essential oil.

Covers to what?

Only if you want to replace a musty smell with a "cough drop/ pain cream" smell.... The musty smell may be there because the stuff was not washed or dry cleaned before storing... and what you may be smelling is old sweat or body oils.... use white vinegar in the bleach and fabric softener dispensers on your washer.... Make sure the sheets, blankets, or comforters are completely dry... the smell may be mildew from stuff being put away damp..... Try spraying all the covers with a good dose of Fabreeze... let dry well before using.... next time you pack them away.... make sure to wash or dry clean them before storing... put dryer sheets between the layers... and use a Space Bag to "vacuum pack" them for storage... it may help keep dampness from getting into them while stored.

what ever your issue id wash it with white vinegar

I responded on the other part of this question. Good luck! :D