Do you mean biblical clean or are they dirty?
They could have some dirt on them.
If you mean biblical clean, some say they are unclean, but most say they are clean.
Depending on what you're using as the basis of "clean" or "unclean", this can refer to food that is contaminated by foreign bodies (viruses, bacteria, etc) or food that has been blessed/sanctioned by a religious body (like Kosher food to the Jews) and that which has been banned.
UNclean
She refused to eat the food because she thought the kitchen was unclean.
clean
Douglas and Harris
It is unclean because it is a catfish
Screaming has nothing to do with clean and unclean vocals. Clean vocals are that of which can be played on the radio and are not explicit. Unclean vocals usually have something that not everyone would find appropriate such as sex, drugs, alcohol, partying, etc. Most albums that have unclean vocals will usually have a Parental Advisory notice on the cover of the album. Also, most unclean albums will come out with a clean version at a later date.
same amount of time it takes to get over food poisoning
The word "clean" does not have a prefix. You have to add one-- for example, "unclean."
Leprosy - To teach when it is unclean, and when it is clean: this is the law of leprosy. (Leviticus 14.57)
unclean...
Dirty, Filthy, unclean