You know, Judy might have been where I discovered above water flooded mask exercises. In fact, I'm sure of it and it's a standard part of my OW course. Go into a kiddie pool... no deeper than her waist... with only a mask. No snorkel, no fins or other complications: just the mask. Have her bend over an put on her mask in the water so that the mask is full of water and then stand right up. She can keep her eyes closed. She can sit on the steps. She can do anything to make herself comfortable. Now ask her about her day. Ask her about little Timmy's performance in school. Hold a conversation with her. Hold her hand, if it helps. Repeat a few times, keeping the flooded mask on her face but her mouth in air. In my OW classes it's usually only after two or three minutes as they learn how to breathe and speak with a face full of water. Yes, I've had to spread this over two/three pool sessions and in that case, I keep it to five minutes or less per session. No need to stress them out. When you're sure that she is comfortable, tell her a joke. I tell the mermaid joke: Why does a mermaid wear seashells? B shells are too small. Nyuk, nyuk, nyuk. Almost every adult 'snorts' through their nose at this joke and they inadvertently clear their mask. If the eyes are closed, tell them to open their eyes. Walla. We keep repeating until they are comfortable talking with a flooded mask and can then clear it with a single try. During this exercise, I watch how the water comes out of the mask. You really can't see it easily under water. I can see if the mask is too tight, if they will need to press on the top of their mask or use another strategy. It's also the time to get them to look slightly up as they clear their mask. Once they are comfortable with that, we continue while floating on the surface. I don't care if the top of the mask breaches the surface. Once they can do this with little or no effort, I graduate them to the big pool and we start on trim and neutral buoyancy.
Why does this work? For a number of nervous Nellies, putting them on Scuba or even a snorkel with a mask full of water is simply too much too fast. Putting a flooded mask on their face with all the air in the world to breathe reduces their task loading to just one thing: not breathing water in through their nose. Just one. They don't have to deal with breathing through a tube... just through their mask without sucking in any through their nose by closing their soft palette. Since I can't always spot the diver who's going to have this issue, I put everyone through this exercise before we get on Scuba. No need to traumatize anyone, and this actually speeds up the entire class when we start clearing masks under water. Since I've gone to this I've never had a single person bolt to the surface on their first UW mask clear. Not one.