Hi,
When i worked in the industry i had to use an analog switch for several different designs in power electronics control circuits.
However, probably the most interesting case was when i did a hobby circuit using analog switches.
This circuit was a membrane keyboard/computer interface.
What i had to do was have the computer read and activate EVERY membrane key switch and associated LED indicators on another computer that was dedicated to playing chess. So we had the 64 keys for each chess board square plus some more for normal control and also some 8 LEDs that had to be sensed.
The analog switches came into play when the host computer wanted to activate a chess board square or one of the control switches. The chess computer would scan each square using a multiplexing technique, and so to 'press' a square using the host computer the square's switch had to be bidirectional. The analog switch allowed this because it can pass current in either direction through the internal 'switch'. So the host computer was able to take complete control of the dedicated chess computer, both in detecting the game being played by humans and also allow playing back that game right on the chess board using the associated LEDs to indicate each move.
So yes analog switches can pass current in both directions. The things to watch out for are bandwidth and 'contact' resistance. The switch series resistance varies with supply voltage on the ones i used which were CMOS.