I have been thinking I would quite like to be able to delete specific items as well. Not 100% sure whether it would help or hinder me though. Maybe I would prefer to be able to delete several mails at a time, leaving a raft more for the general mail washer to deal with.

This sounds like a really good situation where you could use a filter to do the work, it won't be as automatic as a single click but it should accomplish what you want to do.

MW doesn't have that now but it does support the common Windows block select options like Ctrl-A to select all, Click and Shift-Click to select a contiguous group or Ctrl-Click to add individual messages to a group. Once you have a group selected in this way any click in a box is copied to all selected messages.

Delete "selected e-mails" might be the ticket, you click and select one or more messages then right-click to get a delete selected option.

I don't understand the question. I thought you could already delete an individual email by clicking on "delete" or the trash can next to it. I want to be able to delete all of the emails left in MailWasher after you have "washed" the mail into your email program. When you have checked the option in your email program to leave messages on the server, they stay in MailWasher as well, and you have to check each one you want to delete, and then click "wash" mail again. It would be nice if you could return to MailWasher after your mail has been "washed," and just click on DELETE at the top of the column, to remove all of the remaining messages.