This page demonstrates the creation of Proof-of-Burn for Nostr events. Enter an event ID and an amount to burn, and the notary will return a Lightning invoice for that amount (plus notary fees). Once the invoice is paid, the notary will add the event ID to a Merkle tree, and commit the root hash to the Bitcoin blockchain.
Read the whitepaper for more information.
Not really. The coins are sent to a Bitcoin address from which anyone can spend after a delay. This puts the Bitcoin miners in a position to claim the funds first. However, as long as they have not figured it out, really anyone can claim these funds. In addition, the notary will subsidize any transaction that burns less than 330 sats. Thus, as long as there is not much traffic, you can actually steal sats from this service. Enjoy!