If those fish weren't entirely committed to taking the topwater fly, a change to something that runs just under the surface (wooly bugger, bully spider, etc.) probably would have done the trick. The other thing to try is to ignore the standard strip, pause, strip, pause retrieve and just rip it back like a machine gun. If it moves faster, the fish really has to commit to taking the fly without getting a really good look at it.
Bear in mind that this loud approach is better as a technique to use after you've determined that the fish don't want the usual retrieve. Starting with this retrieve from the beginning has the potential to actually spook fish.