Runner-up from Jo:
https://dereferer.me/?https://ormeschool.smugmug.com/Alumni/1971/i-Lvht4X4/

I doubt someone with a removable appliance would go down to the river for a swim with it.  I think she was wired in.  Can't see any bands but it sure summed up the era.

The picture is dated 1974.  I was done with my braces in 1973 and mine might just as well have been wired in, my parents insisted.  But I have personally seen and talked to, at the beach, a kid wearing a facebow but no straps.  We did not discuss his braces but it was not a functional appliance, it was a regular facebow and standard full bands of the time.  There are only two real possibilities, a functional appliance or the facebow does not come out.  There is no reason to wear a facebow without traction.

I vote for wired in.  Here is an interesting editorial from the Journal of Clinical Orthodontics:

https://dereferer.me/?https://www.jco-online.com/archive/1971/06/301

I wore my headgear 20+ hours a day as an adult for 2 years. The last year I wore it 24/7 it was not a big deal tome.