How do I clean a White fir swag?

Can you put it in a dryer with no heat, just "fluff"? When I have things that MUST be cleaned or not used, I resort to a gentle "wash" with a hose or the shower sprayer. If it falls apart, that's OK as I don't want to hang something dirty.

you mean actual fir, like pine needles?

I would take the ribbons off, and throw it under the shower head.

they're not really supposed to last a second year without the greenery being replaced, so I'm super impressed with your storage habits!

Please post a picture of the swag so that it can see exactly what materials it is made out of- plastic, fabric, etc. That way more Hometalkers will be able to give answers to your question that are specific to your needs rather than trying to second guess with suggestions that might not be suitable.

I assume you are describing faux greens. You can loosen the dust with a paint brush and then blow the dust off with canned air, or if you have an older canister vac you may be able to reverse the hose to the exhaust and blow the dust away.

Take it outside,and shake the dust out,then if need be gently rinse in water and dry

Try vacuuming it. Shaking it. If neither works, try a little dish soap and a quick submerge, rinse, and dry on an old towel. Works for silk and plastic flowers, greens and such.