There are several other channels that are active, but as with #SWC-IC it largely is a matter of luck as to whether anyone wants to RP at the time. Typing /list on the chat server will come up with a list of channels you can browse to try to find one that suits you.
#swc-ic seems to be pretty active at least twice every day, but depends on timezones and who's around to RP. It's most likely the most active of the IC rooms. Sometimes you just need to RP an entry and people will appear; other times the regulars may be sleeping. :>