Can I ask a weird question??
If I were to set up Mist on a different computer with a different username, to keep the roaming profiles from getting "mushed" up (yeah....I know that's pretty technical term...LOL).
Set the new version to be PRE-FORK....wouldn't that essentially be a ETC Wallet?
Couldn't I simply make a completely new account and transfer ALL of the money out of the original account (the one with ETH and ETC) and into the new one?
Do the same on the computer with the POST-FORK wallet and now have two completely isolated wallets (one on a machine running PRE=ETH and one on a machine running POST=ETC)? The original "mixed" account would have zero balance in both chains.
Just an idea...
P.S. I tried doing this three times and, unless there's a "lag" somewhere getting the transaction from the Post-Fork ETH blockchain to the Pre-Fork ETC blockchain, I can only see where the coins are moving around on the ETH blockchain. All searches on the Gastracker.io website (the ETC blockchain explorer) don't show any activity in the original account or the new account that I created using Mist with the Pre-Fork option used.
P.P.S. This is a fantastic guide. In fact, I didn't realize I could get my hands on any ETC coins, so this made my day (if I could just figure it out...LOL).
RE: Ethereum Fork: Step-by-Step Guide to Safely Splitting your ETH/ETC