Our merino wool and wool/silk clothing do not need much washing. The natural occurring lanolin in wool works as a self cleanser. You only need to air the item and the lanolin will do its magic. After airing you will find that the clothing smells fresh.
The Irish weather is great for it as airing in damp conditions works best.
As wool loses its lanolin when frequently washed it is best to use a washing detergent which contains lanolin, like this Joha washing detergent. This will restore the wool's qualities.
Make sure to wash the garment on a wool cycle if washing in the washing machine and follow the washing instructions stated on the label.