Irssi can automatically join to specified channels in specified IRC networks. It can also automatically send the password when manually joining to channel without specifying the password.
With -bots and -botcmd arguments you can automatically send commands to someone in channel. This is useful for automatically getting ops for channels, for example
You can also use the -botcmd without -bots argument. The command is then sent whenever you join the channel.
If you want to remove some settings from existing channel record, for example bots, just give the -bots "" parameters to it. Password can be removed by setting it to - (or actually, "" works too).
You can remove the channels with /CHANNEL REMOVE <channel> <network>
/CHANNEL LIST displays list of channels with settings.
/CHANNEL without any arguments displays list of channels you have joined. You can also use /CHANNEL to join to channels just as with /JOIN, like /CHANNEL #a.