If you mean the flokati type, with long "hair" maybe 3 or 4 inches long, then I've been surprised at how well they can come up. You need to use a repeated back & forth scrubbing action, going over every bit numerous times, but quickly (and ideally in a couple of different directions). You can get lego bricks, twigs, god knows what, hiding under the hair - once you've got all of them up, you're about there.