Looking for a way to reduce unwanted reverb from a poorly acoustically treated space.

The venue is a church, and the issue is mostly when there is just a single speaker such as the pastor or reader. The space has a long natural reverb but not in a good way like cathedrals have and there isn't any plans to acoustically treat. I'm wondering if there is a creative way to reduce reverb by using a rear mic out of phase with a delay to cancel out the reverb somewhat?