no Grasswipe -- that doesn't work with Islamists.
What they respect is force & conquest. If an Islamist movement is able to advance their position and gain territory - it is because Allah deems it. As long as ISIS is able to continue to expand, they will be viewed as favored by Allah, and they will continue to gain support of more and more Muslims. If ISIS starts to suffer great defeat, lose territory as well as fighters, Muslims will feel that they aren't favored by Allah, and they will defect. if ISIS is rolled back completely, they will be viewed as a false caliphate, and they will be abandoned entirely.
The only way to make that happen is for forces to beat the crap out of them. "talking" and "listening" are considered weakness.