Similar to what the kid in the Youtube video does, I've never had a problem getting my dragons to drink water, possibly because my 3 (Except the small female I got yesterday) were all adopted, full healthy adults by the time I got them.
The dragons react to movement, by taking a small spray bottle and spraying the water bowl it draws the attention of the dragon who in most cases will come around to inspect it, as the dragon finds the spray and drinks it, it will often find itself drawn to the bowl and start drinking the water collected there.
After a time I've found I don't need that attraction to the bowl to get them to drink and they will do it whenever they find it necessary.
Of course they do bathe in the bowls as well which has me changing the water often.
Ah well, it gives time to interact with the dragons.
-----
2.1 Beardie
1.1 Common Boa
1.1 Ackies