http://health.howstuffworks.com/wellness/beauty-hygiene/uses-for-salt-medical-treatments-ga.htm
Bee stings and bug bites: Work a mixture of salt and water into a paste that will stick to a bee sting or bug bite. Apply the paste, and let sit until dry. This should relieve any itch or pain.
What if such a ingredient can be used as a possible third use to healing HHP? Making a paste out of salt and water and covering the wound with it to prevent infections, in a way restoring HHP? Maybe similarly to Leeches, it should inflict pain in form of SHP loss, but only as a HP restriction.
Say Q10 and under Antiseptic (that's basically what it does) will inflict -10 SHP restriction meaning your SHP can't recover past -10 of your HHP, but can recover your HHP and thus you gain a point of SHP each time a HHP is gained.
Every +10 quality should improve the effect by lowering the amount of hp restricted, and possibly boost the rate and amount of HHP restored.
http://answers.yahoo.com/question/index?qid=20081115142429AAm2g8Z
SALT SOLUTION AS ANTISEPTIC
Now if you were to put bacteria in a surrounding environment where the salt, which is a solute, concentration is higher outside the cell than inside, what will happen?
It is a classic hypertonic solution, where the water will leave the cell and try and dilute the surrounding salt. Because this water would leave the bacterial cell, the cell itself will shrivel and die.
So inflicting SHP harm temporarily to recover HHP is a workable idea too.