I unscrewed the one end of the U-shaped pipe, but can't get the end that slides together out. what do I do??
I don't see why you wouldn't be able to. The same rules apply in the leagues here and I wore a full caged visor too a few years ago. As long as your face is fully covered up, they shouldn't care
Try using a hairbrush (not the on with the tiny bristles) and some Baking sodaof course use water. And then scrub the fur and poops stains or vaccum them up once the baking soda has settled.
