Lent in a Cistercian house is part of the year, not an individual's decision, and Ašič's notes treat it in passing, as a circumstance and not as a subject.
Bitter herbs have the longest tradition in this period. Wormwood, centaury and gentian are traditionally used for a feeling of fullness and poor appetite, of which there is more when the diet changes.
Besides that, the drinking was simple: plenty of warm water, mild blends, nothing strong. Lent is not a time for experiments.
Stična Bitters comes from the same tradition of bitter preparations, though it came about later.
Ašič never wrote about fasting as a treatment. He wrote about it as a part of the year that the body follows.
This answer is general in nature and does not replace a visit to the doctor. The products are foods or cosmetic products and do not replace medical treatment.
