Devotee do the Meditation and goes toward SAMADHI through it.
In Hata Yoga and Dhyan Yoga they Use Tongue as Door Knocker and path maker.
The Parts of HEAD, where the Door of Immortality is placed

How the Khechari Mudra is done by the Devotee, and touch his tongue to its inside nostel bend and tastes and stops leaking of AMRIT. which drops from Bharama Kund
