I've read various ideas on how these remedies work, but none of the explanations really satisfied.
This is how I believe they work.
Everything is vibration.
Everything is vibration, and that includes things such as your emotions, feelings, etc. Hence, guilt would have its own vibrational frequency which connects you to your higher self. Your higher self is like a radio transmitter, sending information to you all the time, but if the receiver (you) gets off frequency, or something interferes with that signal, you no longer are getting the instructions from your higher self clearly, or maybe not at all. The can be caused by shock, trauma, or any number of things that are part of daily life.
Each remedy is the exact frequency as that of your emotions. So taking pine, in regards to guilt, would be ingesting the exact vibration needed to restore the connection and get the signals clearly from your higher self.
Blowing a fuse.
Another way of looking at it is like your connections to your higher self is like a fuse box with thirty eight fuses. If all fuses are working, all the connections are working. But if a fuse blows, then the messages you should be getting for that emotion is interrupted. The specific remedy replaces the fuse. It is possible that more than one fuse might be blown.
This also explains why taking the remedies to prevent feeling a certain way does not work, as replacing a working fuse with a working fuse does not cause it to work any better.