In India they still allow people to ride on the tops of trains - they lose a few every year but it eases the congestion and prevents the authorities having to do something about it.
Suspending a person underneath a single engine helo to perform maintenance duties just because it is cheaper than a twin (especially one with good OEI performance) comes into the same category.
Can you do it? Sure, easy peasy. Should you do it? Not if you value the lives of the poor sods underneath.