I've thought that the following should exist here, and maybe it does and I've just never found it. Do we have a public route to the bit bucket? I'm thinking of an address that uses a publicly known userid. Anything sent to that userid gets tossed immediately upon arrival. No searching. No questions to think about.
The idea behind this is that all of us can give this address to anyone, and the only thing that ever happens is that mail sent there increases the total spam counter. The reason for doing it is nearly zero CPU cycles to process all of this spam, although it would consume bandwidth at our ISP. The address would be hard coded in the software, and only one compare occurs after the userid is isolated. A match says bump the counter and skip to the next msg.