I recommend joinmarket as you can coinjoin any amount & it's much cheaper than whirlpool if you wait for 1 sat/byte.
Good thing with JoinMarket is self-custody. If that isn't a concern go with ChipMixer, as it beats it in both cost and effectivity.
Which node implementation you're talking about? I know Bitcoin Core, gocoin and bcoin doesn't include/add joinmarket by default.
He probably means node OSes implementations, such as myNode, Umbrel, Raspibolt etc.