My response made some general points that I wish were more widely understood:
Pitching matching donations as leverage (e.g. “double your impact”) misrepresents the situation by overassigning credit for funds raised.
This sort of dishonesty isn’t just bad for your soul, but can actually harm the larger world—not just by eroding trust, but by causing people to misallocate their charity budgets.
“Best practices” for a charity tend to promote this kind of dishonesty, because they’re precisely those practices that work no matter what your charity is doing.
If your charity is impact-oriented—if you care about outcomes rather than institutional success—then you should be able to do substantially better than “best practices”.
Copying over my thoughts from a recent comment thread (mostly because of the links to existing resources):