How can I permanently delete emails from the Junk folder?

I have this Apple Script that I use to get rid of emails in my Junk folder that are over two days old. The problem is that it moves them to Trash and I want to actually delete them. Is that possible?

tell application "Mail"

set theAccount to account "Google"

set theMailbox to mailbox "Junk" of theAccount

set theMessages to messages of theMailbox

repeat with eachMessage in theMessages

set messageDate to date received of eachMessage

set currentDate to (current date)

set dateDifference to (currentDate - messageDate) / days

if dateDifference > 2 then

delete eachMessage

end if

end repeat

end tell

[Re-Titled by Moderator]