I practically never receive spam, even on the disposable email adresses I setup for low-security accounts. I only received a few lately, because a relative got his mail hacked. Even then, my ISP’s spam filter blocked out most of it and I never got to see it.
I’m afraid this type of program may have outlived its usefulness in its present form, given a) the efficiency of anti-spam filters now used by mail providers, b) the fact that Mail Washer in not integrated in the mail client according to the reviews here, and therefore the need to switch from one program to the other in order to sort out your mail c) the subscription pricing model and high yearly price.