The Hush power lets you gag all users of a certain rank. The minimum rank to use Hush is owner.
To use Hush, type: "/h?*" into the chat, whereas the "?" is the rank you wish to gag, and the "*" is the duration (in seconds) you want to hush the rank; up to a maximum of 60 seconds. For example, "/hg10" would gag all guests for 10 seconds.
The Hush power smiley has an added functionality, which is that it can be used as a timer. To do this, add #w? to the end of the smiley, whereas the "?" is the number of seconds for the sand to drain out. For example, (hush#w20) means the sand would run out after 20 seconds.