cleaning/ breaking the link with your btc ??

[LamerOnLine]

What is the safest and cost efficient way of cleaning your coins?
I've read that mixing no longer works as technology has advanced to track and can trace even mixed coins. Although this is possible, is it viable, cost efficient for LE?
Trail for me would be > dirty funds > btc in dirty wallet > btc mixer > wallet/s linked to me > my bank account or my btc cold storage for later use
I've also heard an untraceable way is to buy anon altcoins such as monero. So the route would be
dirty funds > bitcoin in dirty wallet >- buy monero, zcash etc > send to another wallet > trade back to btc for storage or sell for cash into my bank account.
dirty funds > buy monero on localmonero > send to another wallet > trade back to btc for storage or sell for cash into my bank account?
Which of these is safest method without loosing too much in fees?
Or any recommendations on another more cost efficient but safe method?