I tried to plant some in my garden some years ago by throwing some seeds around. Nothing happened. Then I managed to get one seedling and poked it into the ground. It has been flourishing all over the place since. Now I have them even in the back lane.
Whenever you feel some itchiness in your throat and it's hot and dry (sure signs of pending sore-throat), just get 5 to 10 leaves, wash them thoroughly, throw them into a cup, boil some water, pour in, cover it for a while until its temperature is down to lukewarm. Then drink it.
Caution: You may scream. Because it's bitter. That's why they call it Hempedu Bumi (bile of the earth). It's an anti-toxin which is good for cleaning out your liver. It also helps lower blood pressure.