 Like other London Quakers, Strettell took a keen interest in charitable works, such as a project to purchase fish and potatoes for the London poor during the severe winter of 1767, and another, in 1777, for the relief of American prisoners of war, held in prisons in England under circumstances of great privation.Strettell died on 20 July 1786.He had not married until he was in his mid-fifties, in 1776.