Hi there
How is MailWasher going for you detecting the good from the spam ? You can set autodelete to have the messages marked as spam to be removed before you see them, which you can do under Settings >> Spam Tools >> Spam Ratings >> you can set the auto-delete option there, I would start iwth a setting of around -140, and perhaps look to pull down to -100.
At those numbers, MailWasher will only be auto-deleting the messages it thinks are very spammy, if it comes a message that is a bit spammy, they would still show in MailWasher.
Cheers