Stop spreading false information. Mixers are not scam. He can use a reputable mixer. It will have onion link and he should use Tor to access the onion link. I will not say that you do not know what you are saying because you know about this very well, so I will say you should stop lying.
I'm not lying, here's proof:
Destroying the session deletes chip private key.
Really fucking bad practice of ChipMixer to keep private keys, not gonna lie.
I'm going to stand by what I said: it was a
bad practice from the side of ChipMixer, but it's not a flaw in the concept of centralized mixers, in itself.
If a service does everything correctly (including deleting private keys and any backups after handing them to the user), something like what happened to CM could simply not happen.