So I went an bought one made by "Onn" from Walmart Canada for testing at home.
This thing has a rubberized grip, yellow screw-on tip and yellow safety string/lanyard, and secures to any standard camera casing.
It floats perfectly with the Osmo Action attached. The end is clearly visible in water and sticks out about an inch.
I screwed the plug on tight and left it floating for about 10 minutes - no water inside the handle. (Thumbs Up)
Camera attachment seems solid (plastic) and is likely fine for light use (perhaps not water skiing as it may break if you fall in the water -- or it may not - I'm not testing that), but I did need my Osmo Action's bolt/pin as the one provided is too short and hits the OA's case as you tighten.
I paid $10 CAN at Walmart Canada.
Onn Floating Selfie Stick