Hello EM.
First of all, I wish you the best in the battle you are about to take!
I've been studying also some processes that deal with the dew and it's salt because in my perspective it applies to the works i'm currently developing too. Although I believe it can produce a stone I found it extremely long (considering zero fails and knowing what one is doing). Sure today we don't need to exchange the vases between new barrels with horse dung,

but from the specific stoppers to be used that have to be hand made (the ones that permit it to exhale but not too much) to the number of vases you need to use with different samples etc. I find it very hard to perform. You need a lot of salts, from hundreds of liters gathered in the correct time of the year... let it putrify... gather the "gelly"... work it, get the salts... work te salts etc. All this will take months, and the matter it's not even in the flasks.As I sayd, I find it extremely long and hard to perform without someone to teach you if the materias are still "green" or "mature" etc.
This book is very specific also about this matter
Another Error is in those, who seek for this Dissolvent in Dew and Rain Water, not considering, that this was designed only as Nourishment for the Vegetable, having but such a Portion of the Universal Fire in it, as might serve to dissolve the Salt Nitre of the Earth, and then the Vegetable Seed in order to a new Production; this Fire or Dissolver being Far Remiss to that of Animals, as that of Animals is to Minerals, cannot be the Philosophers Subject of this Dissolvent (...) for Life would be too short to extract it.
I believe this phrase "for Life would be too short to extract it" should not be taken literally. I believe that what he is saying is something like "I dont have the needed patience to perform all the previous and later works". Because he knew a faster way.
From: SANGUIS NATURAE
"For the Power and Virtue of this Living Fire is so great, that if
it were absent, the Elements would be dead, especially the Heaven, an’
Element which most of all stands in need of this Light. Having passed
through the Heaven, it comes into the Air, that great work this Element, and insinuateth it
self most intimately into it. In this Element the Virtue of this Fire doth
chiefly manifest itself; because in it is inspissated, and constituteth
the vital Air; which Air is thus agreeable to the Creatures, for
sustaining of Life. For this living Fire simply is not convenient for the
Creatures, nor yet the Simple Air; but Fire consealed with the most pure
part of the Air, and Air impregnated with the Coelestial living Fire; and
so they Constitute vital Airs, which every living Creature receiveth for
the Conservation of its life. This living Fire needeth the Soul of the
Elements, chiefly of the Air, which it makes use of for a VEHICLE, that
thereby it may more easily enter into the other Elements, that is to say
first the Water, a subtile and this Element, in which it is yet more
inspissated, and taketh a more gross Body of which it standeth in need for
irrorating of. all Terrestrial Things, especially Salts, Minerals and
Stones; all which need such irrigation; thus being clothed with a thick
garment, it passeth into the Earth, a dark & thick Element, and of a very
powerful fixing Virtue; and there it puts on a saline Body, which
predominates over all things, and contains the rest of the Principles,
which it had received in the Air, Heaven & Water(...)
I tend to agree... Through the action of Fire, Air transforms itself into Water. Water then permeates Earth.
I think the links between fire, air and water (the first "substantial" element), I mean the natural process that allows this to happen, hold an important key regarding how the SM used the Vehicle. Fire and Water don't mix they need a mediator.
Fire and Water don't mix... each one pulls to the opposite side. They create tension. Always found it interesting that "SM" in the coat of arms placed on the "chariot" or "vehicle" that carries the "king".
C.