Below is an article on facial / throat exercises for sleep apnea. It addresses the issues with the tounge and the strength and placement to improve obstructive sleep apnea. Once FCR corrects the nasal airway and widens the maxilla then these exercises are prescribed. The results are in the 90% with the combination of both.
Dr. John Lieurance
This is an exciting alternative to CPAP, which many patients dislike because they have to wear a mask that blasts air down their throats to sleep. If they are willing to be compliant with exercises that strengthen their throat muscles and reduce their neck size, then I would certainly refer them to the following video below for some example exercises: