I found it! This can almost not NOT be it! You are looking for The Dream Merchant, a Dutch novel by <PERSON>. It's original title was De gevleugelde kat (translated: The Winged Cat) It was first published in 2002.
For some reason your description of the snake bracelet triggered a memory, but I'm 100% certain I've never read the book before :)
Twelve year old <PERSON> is contacted by a corporation called Gippart International one day late at night. <PERSON> and his friend, <PERSON> go to Gippart and meet <PERSON>, a talent scout. <PERSON> is sent into a dreamworld to sell products. But dreams also come with nightmares...
Umaya, the collective dream of everyone at that point in time, is caught between dreams and reality. <PERSON>, <PERSON> and a fellow associate <PERSON> cannot get out of the dream-world, where time is running backwards due to a Gippart employee attempting to break into real time rather than dream-time. Along his adventure, <PERSON> meets his dead twin sister <PERSON>, who has been attempting to get in contact with him for 350 years. But with <PERSON> comes <PERSON>, a guardian who makes sure that no one crosses the borders of life and death.
The members of this troop find themselves with powers that they cannot explain. 322
<PERSON>, the first to find his powers, can control dream time by listening to the rhythm and matching it, causing it to slow, stop, or even rewind. <PERSON> changes Umaya with words, influencing people and surroundings to her will, she is the group storyteller. <PERSON> is a thief and can change the very nature of things just by looking at them. However, they are trapped in umaya, the dream-world.
The four children must find <PERSON> at the end of time and fulfill <PERSON>'s last promise to Temberi. They learn about each of <PERSON>'s six kids and put together the clues that each of them hold.
After a harrowing ordeal, <PERSON>, <PERSON>, <PERSON>, <PERSON>, and <PERSON> manage to find their way to the edge of time itself, where the Tembe people live in a crumbling Fortress. The Tembe, descended from Temberi, have been trapped at the edge of time for over 1000 years. Luckily, the Tembe are friendly people, and show the associates how their Fortress is slowly being ripped away into the hurricane whom they have named Satura. Using the powers they gained in the journey, the children manage to find their way through the hurricane back into the real world.
I found in on Google using this search query: "book dreamworld snake bracelet" 322