Versluis vs. Hanegraaff (not sure he understands emic vs. etic here)

Still, one has to wonder about the implications of the sharp division he makes between a “religionist” perspective and an “empiricist” one. Let us consider, for a moment, the example of an alchemical treatise. It may well be that this treatise includes arcane allusions to alchemical work that only a practicing alchemist would recognize and understand. We could envision an etic approach to this treatise that completely fails to recognize what the treatise conveys on alchemical discipline, whereas an emic approach might very well be the only one that could get at what the alchemical work is actually about. In this case, as in a number of others I might also cite, a sympathetic empiricist perspective may well be indispensable for understanding the work one is investigating. And this, in fact, is the methodological approach that I am advocating here.
Methods in the Study of Western Esotericism

Zodiacal Man

Adam McLean on the "Frater Albertus" school

"Yes, it is good to see some researchers revisiting actual alchemical
processes and attempting to repeat some alchemical experiments
described in the original writings, books and manuscripts of alchemists.
Unfortunately, as these often involve high temperatures, molten metals
or salts, corrosive acids and alkalis, as well as poisonous volatile
substances, these can only be undertaken in a properly equipped
chemical laboratory.

From the 1980s, there was popularised by Frater Albertus in the USA
a type of kitchen chemistry, involving simple low temperature distillations
of herbal material. This was presented as an actual "alchemy" which could
result in plant stones and various such preparations which people were
led to believe could cure them of illnesses. Sadly, this was mere froth and
fabrication and had almost no connection to anything one might recognise as
being recorded in actual alchemical writings. During the last 30 years, this
Frater Albertus concocted "alchemy" seems to have been the one which
has become the popular view of practical alchemy, and is trawled through
in study courses and various web sites.

The important thing, surely, is to explore the original writings of the alchemists
and also attempt to repeat their experimental work."

taken from a comment posted here