Trivia: In the opening credits of Hitman, there are several scenes involving children training. Many of these scenes were from footage from the first season of Dark Angel (appeared on Fox on October 3, 2000).
Trivia: When 47 crashes through the hotel window and the kids turn around, you can see that they're playing a videogame. The game is "Hitman: Blood Money", the first mission to be exact.
Answer: The reason for the beads being put down was so he could hear if someone stepped on them. Notice how he heard them after Diana said his location was compromised. The beads never released any gas. The smoke filling the room could have either been caused by the explosive device he attached to the door which set most of the room on fire or, they could have been smoke grenades throw into the room by the FSB in an attempt to apprehend 47 although they were unaware he had already escaped.