Lots of opinions related to your question. I'll give you my nutshell take.
Assuming that anytime you rub any type of detailing clay or synthetic substitute, you're going to induce clay marring. Maybe not on hard paint, but everything else - yes clay marring. You can't always see it on light colored paints, but that doesn't mean it's not there.
This is why I practice, teach and preach, if you're going to do any type of mechanical decontamination to automotive paints, then you should have already factored in doing at least one machine polishing step to remove any accidental marring and prefect the paint.
The above said, here's my take based upon my real-world experience. Of course, there are thousands of experts on social media that may and often times will disagree with my position and that's fine.
1: The safest way to remove contamination off of soft paint is using an Ultra Fine Grade Traditional Detailing Clay.
2: Synthetic clay substitutes, Clay Mitts, Clay Towels, Clay Blocks and Clay Discs are all a better value than traditional detailing clay simply because if you drop any of these tools onto the ground, you can wash it off and re-use it. If you drop a piece of clay onto the ground - you really need to throw it away as the risks for putting scratches into your car's paint are too great due to contamination that will have stuck to the clay.
3: For really stubborn contamination, like overspray paint, I have found an AGGRESSIVE clay is more effective than any synthetic clay substitute that I've used.
So in practice, it's a good idea to use the right tool for the job.
There is a Rabbit Hole a person can go down as it relates to soft paint and doing the mechanical decontamination process during the washing step - but I don't have time to go down that Rabbit Hole today.
Mike
