Powerful Detergent That Stains Clothes White
Puzzle 11 of Day at the Museum Easy Pack
Question is: Powerful Detergent That Stains Clothes White
and the answer is: BLEACH
Word Meaning:
BLEACH — (uncountable) A chemical, such as sodium hypochlorite or hydrogen peroxide, or a preparation of such a chemical, used for disinfecting or whitening.
Definitions from Wiktionary.