The Only Use of

fastidious
in
Unbroken, by Hillenbrand

All his life, Louie had been fastidious about cleanliness, so much so that in college he had kept Listerine in his car's glove compartment so he could rinse his mouth after kissing girls.
p. 286.7

fastidious = excessively concerned with cleanliness

Definition:

giving careful attention to detail

or:

excessively concerned with cleanliness or matters of taste