Users should label some UTXOs as “octojoin” so that they can be used in octojoin transactions. Ideally, these UTXOs should be ones that have been swapped with others and are linked to someone else’s transaction history.
Input Obfuscation with Off-Chain Swaps
Do off-chain swaps (e.g. statechain, submarine swaps, or coinswap) to obtain UTXOs with different histories. Ensure that all inputs come from other users except one belonging to the sender, making it difficult for on-chain analysts to determine ownership.
It's interesting approach to confuse blockchain analysis that the UTXO multiple belong to different people. The trade-off between multiple participant (in PayJoin) and having multiple UTXO from different source (Octojoin) is acceptable, if user properly label and group their address/UTXO.
This is interesting, but I couldn't find any wallets yet that have this feature to test it out.
Based on link shared by OP, it's not exist. If you really want to give it a try, check
https://github.com/octojoin/poc. But i only find very minimal explanation about using it.
P.S. This thread is more suitable on "Development & Technical Discussion" board.