cannot remove irc channel of offline account?

[Dennis Knorr]

Hello,
i have a funny problem with pidgin. I connect to a IRC-Network and 
automatically join a (now big) list of channels. when pidgin tries to 
join the channels after sending the password, the irc-network closes my 
connection because of excess flood. But i cannot delete the channels in 
the offline-mode of the account (in the gui), so i cannot rejoin the 
network without getting kicked out.

Does anyone know this behaviour and how to delete channels off an 
offline account without fumbling around in  ~/.purple?

Thx