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I have yet to write a post about this, but I have experimented with using the elements for short-term, non-permanent healing. Because a permanent solution is not being sought, this helps give a strong effect from a relatively low amount of energy.
For example, chanting Jala and using it to clear pathological heat in the body (like skin redness or inflammation), or using Prithivi to restore the yin of the body or particular organ. Usually, immediately after using either of these, I would feel instant effects, as well as a delayed reaction. For example, a calming influence across the body, then later the yin quality of my skin would improve.
Of course, the solution is not permanent, but it doesn't need to be, because the body can sustain a baseline level of health. Just as you suggest supplementing collagen, this is the same principle, but with a spiritual "supplement". Unlike physical solutions, the energy can go right where it is needed in the body, getting around physical obstacles.
If you are curious, this is what exactly I did: Prithivi 5, 10, or 20 times, then "This earth energy has now restored the yin of my body, in a manner that supports both my health and productivity (helps prevent sluggishness)" x3
Then I visualized it like blocks of nourishing earth rebuilding the structure of my bodily tissue.