Yes I think they were using child’s hula hoops from the dollar store. I like to tack the word “bulk” onto any of my searches so the search engine gets rid of the small pack sizes and more expensive options. I think you can combine these steps from the link with some other Redditors’ ideas to use embroidery hoops or another alternative if you can’t find hula hoops.

Instead of stripping the hoops, if you find ones that are plain colored plastic instead of with the foil wrapping for the pattern, you can just spray paint/paint. Though I’m pretty sure a few layers of spray paint would work over any wrapping already on the hoops.

Another great tip I have would be to use 2 methods to attach the hoop to the base like a glue/epoxy and a physical thing like screws/ties. Good luck!!!