Question PEX: interact.dispenser based on its content

It's the first time that I use PEX plugin (Permission EX). There are a lot of commands and configurations very useful but, what I want to do is a little more tricky.. Is there any way to revoke permission to interact with a dispenser with a lava bucket inside? I don't want to revoke every interaction with dispensers because they would be useful for a lot of other things.. I just want to prevent a bad behavior for a particular group of users!

Let me make some more examples:
User triggers (buttons, pressure plates, etc) a dispenser with a lava bucket inside - REVOKE!
User triggers a dispenser with a water bucket inside - NO PROB, YOU CAN DO IT!

This is the general command to revoke access to dispensers, any help?

Code:

-modifyworld.blocks.interact.dispenser

 

@hiru, it's not designed to work like that, sry