Dust Expiry: Clean the UTXO set from spam

The term "deterministic" in the context of handling dust transactions on the Bitcoin network refers to a method where transactions that can be conclusively identified as spamming the network, particularly those that do not contribute to Bitcoin's primary monetary function, are targeted. This implies the utilization of a specific function or algorithm, referred to here as a "spam-checking-function f," that when applied, consistently identifies certain transactions as spam with absolute certainty, rather than on an occasional basis. The curiosity arises from understanding how such a function can reliably segregate spam transactions, especially given the inherent challenges in designing fully objective and unfailing mechanisms for this purpose. Despite skepticism regarding the feasibility of such a deterministic approach, the inquiry seeks to delve deeper into the rationale behind its proposed effectiveness, particularly in distinguishing between transactions that support non-monetary activities external to Bitcoin's intended monetary role.