Long term nasal user, basic issue when trying full-face

[sawinglogz]

Tongue Suck Technique:
Place your tongue to the roof of your mouth with tip of tongue behind front teeth.  Slowly suck upwards and back.
This places the tongue in a natural position, with the back of tongue sealing the back of the throat so that if you open your mouth/jaw while sleeping, no air will escape.

Do people other than me actually manage to maintain this while asleep? My tongue relaxes when I'm asleep, and the positive air pressure then pushes it away from the roof of my mouth.

I've heard of this trick, but I find actually maintaining it mystifying.

[sheepless]

this is probably not the place to have this discussion but...

I can't do the tongue suck technique to save my life, awake or asleep. I've concluded my tongue is simply too big for my mouth, which is consistent with what dentists and orthodontists have told me since I was a child. I have to curl the tip up or down or it'll expand laterally between my molars and I'll wake myself biting the sides of my tongue.