Using a neutral, mild detergent, that is preferably Woolmark recommended, should be your go-to when hand washing or machine washing wool clothing.
Avoid using heavy-duty detergents, “Bio” detergents containing enzymes, or any detergents containing bleaches. Never use bleach, either chlorine or oxygen based, when washing wool.
If powdered detergents are used, it is always best to pre-dissolve the detergent prior to adding to the wash. This helps to prevent concentrated specks of detergent from coming into contact with the clothes, which may cause holes.
Final rinse softeners or conditioners can be used, but care should be taken to keep the amount down to minimum. An excessive amount of softener can lead to the formation of pills during subsequent washes - this is because softeners tend to act as a lubricant and enable fibres to move out onto the surface of the sweater more easily.