Frank J. Wilstach, comp. A Dictionary of Similes. 1916.

Insipid

Insipid company as a looking-glass.
—Earl of Beaconsfield

Insipid as an old acquaintance.
—Colley Cibber

Insipid things—like sandwiches of veal.
—Thomas Hood

Insipid as a garden much watered.
—Horace

Insipid, and dull as a drone,
Though near to each other
As sister and brother,
They both take their airing alone.
—Robert Lloyd