Methods for removing phlegm recommended by UK hospitals

Recommended by hospitals in the UK
It is said to be how to remove phlegm.

There is actually a technique called Happing.
Like blowing on a window to fog it up~!!
If you spit it out, mucus moves easily from the lungs.
It lifts you up.

Using this,
It's a method combined with blowing through a straw.
Supplies are ⭐️
Straw, a water bottle filled about two-thirds with water
Those are the two endings.
(Water bottles are over 1 liter)