Sure, something like this might be possible if you can find a VPN or proxy that isn't blocked by freenode. But I'm not really looking for a workaround for myself, I'm more interested to see what can be done to fix this for other people in the future.
I think using GPG authentication and the Web of Trust anonymously is something traders may reasonably want to do, and at the moment it's not really possible.
Some possible ideas:
- Move the trading channels off freenode to some other irc server in the future (irc.bitcoin.org?)
- Provide a web interface to gribble somehow.
- Someone provides a web interface for creating accounts on freenode.