There were several avenues of escape. The davidians, except for three chose to not come out. Th compound can hardly be called an enclosed area because of the size, the windows and the number of doors to the outside.
I have no experience with CS whatsoever...I do however remember the Waco disaster...It was claimed at the time that the tank that breached the building in many places was pumping CS gas into the structure and it was said (by some) that there were over 400 canisters of CS gas that landed inside the compound...The FLIR videos showed cannisters being fired into the buildings and fires starting...
They appear to have different types of CS gas...One is the normal stuff and another is pyrotechnic or incendiary gas which is used to start fires...
Incendiary CS was used a number of years ago to burn out a killer named Dorner from a cabin he was holed up in...
If one digs deep enough he can find where both kinds of CS gas were used at Waco...