I am glad you liked this area but at the same time I laughed out loud because you mentioned Charas or was that Bhang? WE do have it a plenty on the roadsides from where people extract it by rubbing the leaves with their hands. I once used it by mistake while going for a game of badminton and won the first five points against a champion player and then I don't know how I reached home...lol.

I suggest you to buy "Doaran O" tablets and eat one half an hour before you start traveling in the hills. You will never feel like vomiting, but enjoy your journey. Finally, If you go to Shimla from Manali, try to travel by train passing through 100+ tunnels and no feelings of vomiting at all. All the best!