To preserve the innate properties of milled loden it is the best not to dry-clean it extensively.
Milled loden can easily be hand-washed as needed in luke warm water using a special wool detergent. It is the best to turn the garment inside out, to gently move the item through the water avoiding any rubbing, stretching or wringing of the fabric. Gently squeeze out the water and then roll the garment up in a 
bath towel to gently remove any excess water. Lay flat to dry in a well-ventilated area.
The most natural is when you just hang the garment to fresh air. If there's a stain on the garment it is generally sufficient to dab this only with some gall soap and water.
If you heed this your Hilda.Henri piece will be a faithful companion.