you can unblock the hole using a small clean pin and wash it under running water.
The holes tend to stay clear on heavy days ime, but I always wash it out each change using a bottle of water.
I've used a mooncup at work, at A&E, home, in public loos at cinemas, retaurants, museums, I tend to carry a handbag and have an empty bottle in bag which I fill with water from the sink on my way into toilet cubicles in public toilets.
when you put the mooncup in give it a final twist to create suction effect, it should stay put, not ride way up.