in real iron palm training,yes it does increase striking power.as real kung fu practitioners such as sifu gino know,iron palm is not just hitting a bag with a certain medium and applying jow. there is much more to it than that.
as far as jow and science goes,i think there are some studies as to its effectiveness.if i can figure out how to pic off my phone i will show effectiveness firsthand.my aunt fel and bruised herself badly. i applied jow and 36 hr later most were gone and the rest had faded tremendously. i dont need some scientist to tell me if something works when i have experienced it. it wouldnt have been used by,monks warriors and emporers alike for 100s of years if it had no efficacy.