Giantess in Timberland PRO Boots Crush Pebbles & Rocks This was a custom video: Casual walk on a road of dry fine gravel for around 10-12 minutes with Timberland Pro. Then, walk on the side of a paved road alternating between gravel and pavement to hear the crush of any pebble that could have gotten stuck. That second part could be at least 5 mins, but you could do it longer if there are loud crush noises. If by the end of the gravel road walk you haven't catched enough pebbles, feel free to add a few bigger ones between the treads of both shoes before starting the walk on pavement.