Hotels and guest houses do not necessarily have their own laundry, four stars or more will generally have, detergents are generally laundry detergent, oil emulsifier, bleach, neutralizer, softener, powder, etc., these high-level laundries will be used with all of these products, their washing is not cost, the price of the detergent and the quality of the requirements is not what they care about, the industry basically know that the rules of the trade. The first time I've seen this, I've seen a lot of it.