just load what ever sample you have, even it you have sliced it up somewhere else, and you can either just use the slice you created or you can dump it into the fruity slicer and chop it up even more, just make sure your sample is measure in bars, ex. just make sure it is at least a 1 bar, 2 bar, 4 bar sample, so it will know where to cut your your sample.
I'll just cut a 2 bar sample and just lay it down in the fruity slicer all the way across until it is like it did nothing to it, and just mess around with it, dont know if this helps?