The phrase "virtuous example" is correct and usable in written English
You can use it to describe someone or something that is an exemplary, admirable model of behavior or a quality. For example, "The distinguished professor set a virtuous example for her students, demonstrating respect, dedication, and hard work."
Although there are some virtuous examples of water reuse projects in the world, there is still much to be done, especially in terms of incentives and economic viability.
I would argue, however, that such teaching need not be formal - we should teach virtuous humor by example.
One of the reasons the Catholic Church names saints is to provide the faithful with human role models who tried to live virtuous lives, whose examples we may choose to follow.
Erasmus even questioned whether Christians should be planning war against the Turks, who might be more readily won for Christ if Christians gave an example of virtuous living.
For example, the virtuous person may not be able to list some further fact concerning the circumstances of various people in a crowded railway carriage, but the fact that a particular passenger is over-burdened by their bags and in some discomfort because they have to stand may weigh with this person.
The nice guys are hardly few and far between, as Mr Handy's many examples of virtuous companies illustrate and they are not finishing last.
"It's seeming to be virtuous that helps; as, for example, seeming to be compassionate, loyal, humane, honest and religious".
Reich describes this as an example of a "virtuous circle" in which productivity grows, wages increase, workers buy more, companies hire more, tax revenues increase, government invests more, workers are better educated.
Clarissa and Lovelace seem at first to be, like Pamela and Mr. B, a familiar if well-rendered example of a virtuous woman and a marriage-resistant playboy, but their fully elaborated inner worlds begin to transform them into beings far more ambiguous.
Education in virtue can be provided by parents and teachers, by the example of the virtuous actions of the people around us (De communibus notitiis 1069A), by the law of the cities (De virtute morali 452D), and also by philosophy, poetry and history (De profectibus 79B-80B).
