Original sentence: It is not only a rip-off, but can also be dangerous to people's health if plastic or other doubtful agents are used.Unscrupulous hashish dealers sometimes repowder the hashish, mix it with a foreign materials  such as soap, or boot wax, and re-press the mixture into a hashish block, which is sold as if it was the pure product
Edited sentence: Dealers sometimes repowder the hashish, mix it with a foreign materials  such as soap, or boot wax, and re-press the mixture into a hashish block, which is sold as if it was the pure product.This can be dangerous to people's health if plastic or other doubtful agents are used