Certified GKH Gardening Expert
Since you say "selective," I understand then that you cannot use a product like glyphosate or solarization because you aren't killing out an entire section. The article below says if your lawn is more than 40 percent kikuyugrass, you should just let kikuyugrass be your primary grass. Using a selective postemergent herbicide repeatedly plus spot selections with glyphosate are suggested.
Chemical warfare for Bermudagrass is also recommended.
These articles should help: