The labour ordinance always provides only very brief guidelines. Its not an cyclopedia. And there is never any specific terms regarding detailed things like washing liquid, etc. It all depends on how a reasonable man interpret it. Lets take it like this, without a washing liquid provided, it won't make the environment an improper place for a reasonable man to live in . This is unlike food, stable sleepng place, privacy, etc which are definitely needed as the basics and human rights for a person. Or, take it another way, if an employee sues an employer for not providing washing liquid, the amount involved would be minimal and is unsound/ridiculous to be called a claim.