How to make a droplet on mac osx with automator?

I readed some tutorials about making droplets with apple script or with automator's help. First, I need to know if these droplets only works with the drag n drop file action, or if you can do the action in the current directory you are.And if the last answer is yes, how to do with automator? This was a general question.

In my case. I need a droplet in my finder toolbar that when I click on in it search for all file with a specific extensions and drop to trash. I try with automator but I can't fine the action for selecting files in the current directory, only found the general find. Because I will can be in any other possible directory I need to know how to do this. It's not a problem writing some applescript, I 开发者_StackOverflow社区don't know it but I can learn:)

To create a droplet with Automator, you select application, when Automator asks you what you want to create.

The description given by the application, when you select application is the following:

Applications are self-running workflows. Any files or folders dropped onto an Application will be used as input to the workflow.

I think it means that only dropped files / directory will be passed to the workflow. I tested it, and I can confirm it works in that way.