I will leave this here for now - on various fabric chemicals FIXATIVES, WASH, SOFTENERS. Hermes uses commercial equivalents .. Their process - see what little they say in all their YOUTUBE videos is applied to raw silk - wash, print, steam , wash ...
Ignore the metiers videos where the wash steam is not done.
Are they the same or different? Retayne, Synthrapol, and Color Catchers While the quality of fabric has improved over the years, many fabrics still bleed. As discussed in the blog post from 16 October 2020, To wash or not wash your fabric, that is the question!, when fabric is washed, some of...
lonestarquiltworks.com
https://www.dharmatrading.com/chemicals/milsoft.html
The interesting bits I noticed are
1. RETAYNE - FIXATIVE - treated fabrics must be washed in COLD water
2. MILSOFT - SOFTENER - leaves a residue on the fabric
3. SYNTHRAPOL - WASH - use 140 deg F water - to me that is HOT
4. MODERN washers eg FRONT LOADERS should not be used , water is not HOT enough, or there is not enough water pressure - do it by hand
If you want to soften a scarf, depends on how Hermes treated it to begin with ...