once again see edwardt's post

parrot here :oD

system runs hot, makes compounds added to propane separate and it is like an oily residue that builds up. I've known some people to add an inline thermostat inline with the hoses to the regulator to help keep it cooler.

To clean it use a contact cleaner or some sort, something that evaporates fast and is non corrosive. Harsh chemicals will damage seals etc so stay away from them. Brakecleaner? carb cleaner? bad bad bad

good luck