It sounds like you are agreeing that training the blocklist works. To control where messages are moved you can use the Move it to the Trash if the spam score is at least setting. Set it to 99 (blocklist) if you want only the blocklisted messages to go to Trash. There’s also a note on that page about how to make the rescue script also move blocked messages to Trash, if you’re trying to get SpamSieve to move messages that another filter put in Junk to Trash. We previously discussed that here.