Good question. Each visitor gets a dedicated channel. It makes it easy to respond back to them. When conversation is ended, we archive the channel. If they ever come back we unarchive it and you have previous chat history.
If you're creating an entirely new channel and archiving it every time, does that mean my archived channels list will be full of potentially thousands of channels? Ignoring that I'll struggle to find channels I may want to revive (we archive channels a lot here), will Slack cope well with this? (We've seen what happens if they have over a certain user count.. so I'd be worried what would happen here.) Is it possible to entirely wipe a channel after a certain period of time rather than archive?
Update: OK, I'm an idiot. I just realized I could spin up a second free Slack account just for this use..
I run this small email-helpdesk<-->Trello app [1] and I thought I was the only one trying to come up with the best ways to map features from what Trello has builtin to what my app needs.
Users sometimes find it awkward, but in the end it works very well.