Need some help with deleting folders

Ok, I have read the nested folders instructions but still have some questions. Here is what I am trying to do.

I have a "Downloads" folder that may contain files of interest or folders that contain files of interest (along with other files).

I want to look for files within the "Downloads" folder that have a certain extension and rename & move them. I then want to go into the sub-folders and look for files with that same extension and rename & move them too.

I think I understand how to do that part by having the 'match extension & rename' rule first followed by the 'go into subfolders rule next'. Now, what I want to do after this has completed is to move the remaining folders within the "Downloads" folder to the trash (whether they are empty or not).

This is what I am struggling with.

If that makes sense, any ideas?

You can have a rule match those folders but make sure it appears before the "Go into subfolders" rule, as most people have that rule set up to match all folders.

I'm still not quite understanding. In your "processing subfolders" explanation, you delete your empty folder after processing the contents. I understand this, however in my case, the folders may not be empty after I process them. So, I'm not sure what rule to match a folder unless it is simply 'if folder, move to trash'. However, if that comes before the "go into subfolders', wouldn't that delete the folder before the contents get processed?

UPDATE:

Ok, think I figured it out. I did just the opposite of how I was looking or files to rename based on extension. I said if the folder does not contain files with those extensions, then send to the trash.