That’s a great way to get sats. Be mindful of how you send him the BTC, though: Ideally the UTXOs are first mixed and then sent to your friend over lightning. The best desktop app for mixing Sats is definitely Sparrow Wallet. You could, instead, just send any old sats over lightning and have some level of privacy, though not as much privacy as if you had first also done a coinjoin mix via Sparrow