Gross Beat is a huge time-saver for glitching, scratching and related time/volume based effects. While it's fun to use live, one of the most precise methods is to use the Fruity Keyboard Controller or an Automation Clip to switch envelopes (Time and or Volume) in sync with the project. This video shows you how...
Gross Beat - Scratch, Glitch and Mayhem Powerhouse
If you are using the live keyboard control method you can download a Gross Beat preset 'Momentary' from Looptalk, thanks to nucleon for providing it. This releases the preset slot on key-release so you don't have to press the slot 1 again to turn off the selected slot.
Bit thanks to JWMMakerofMusic (Jim) for the loan of his cool 'Kowloon' track used in this tutorial. Here's the original (unmolested version) of Kowloon: