In any OSX “document window”, there is a little icon representing the current document. If you click and hold this icon, it becomes a draggable alias for the file. You can then use that alias much as you would the file itself (as if you had dragged it from the finder) - but one thing you can’t do is delete the file by dropping it in the trash.
Trashy is a simple program to fix that. Put it in your dock, and it will send anything you drag onto it into the trash. Click here to download Trashy.
Here’s the entire source code applescript, if you’re curious (or just naturally suspicious of running random programs you found on internet, as you ought to be):
on open fileList tell application "Finder" repeat with f in fileList set n to 0 repeat while class of f is alias file if n is less than 5 then set n to n + 1 set f to original item of f end if end repeat move f to the trash end repeat end tell end open on run tell application "Finder" to open the trash end run