Part of my occasional "Will It Whoosh" mental warm up, where I take 10 minutes to put something on a string and twirl it in front of a microphone to see if it'll whoosh.
A squeaker (as you would find in a giggle tube or a stuffed animal), on some monofilament fishing line (not the best choice as monofilament is kind of whistle-y).
Does it whoosh: yes
Download it. Use it. Let me know.