Are either of these products harmful for the paint surface in any way? Seems like they both might have a tendency to trap particles and lead to scratches.

Works great in combo with a synthetic chamois for drying those areas the water blade cannot reach. I use the P21S drying towel but have heard great things about the water bandit.

..and they both work great. I have had ZERO problems. However a neighbor has a scratch on his Z3 from the CA waterblade.