Being honest.

I advertised my vacuum cleaner on Freecycle with the headline: OFFER: One used, worn out vacuum.

And described it like so:

I have a Eureka Whirlwind that's about 2 years old. We have 2 dogs, 5 cats, and no grass. There has been an enormous amount of sand, hair, dust, and Lord knows what else sucked up through this thing. It has lots of suction. The thingy turns. I've looked high and low and everything seems fine. But it's not picking up. Perhaps you'll have better luck figuring it out.

I’ve had no takers. I can’t imagine why. I wonder if the recycler will take all that plastic?