If a vehicle needs actual, serious decontamination, I do what the automakers both do and recommend- I decontaminate it chemically, usually with the same ValuGard ABC that`s been approved for use by virtually everyone.
Clay- I used tons of the Griot`s and found it awfully similar to the Mother`s. Worked OK but I don`t like using SpeedShine for the lube. These days I use Sonus SFX and the Ricardo/Smart clays. I find the Sonus works best with their Glyde lube.
Sonus SFX is gentle enough that it`ll "clay the LSP clean" without stripping it as long as I do it right. When I did some experimenting, I could use it gently enough to not even strip Meguiar`s M05 although I was being so gentle that I probably wasn`t doing much decon either.
For actual decontamination of the paint I use the Ricardo/Smart clay as the SFX is just too gentle for that when used properly.
Neither of those clays will mar my paint as long as I do things properly but every now and then I do get an !oops! If I`m lucky it`s only a tiny, short/shallow thing that nobody else will ever see. IMO any kind of mechanical decontamination runs the risk of marring.
Not interested in using the towels/etc. if only because I can`t grasp the concept behind how one could use them without a (greater) risk of marring. Even the product literature says to *NOT* use such stuff on satin/matte/flat finishes as it might mess them up through, wait for it...polishing action (AKA, *ABRASION*) so I can`t see how it`d magically become safe when used on some other surface. I guess it`s not as big a deal for people who are already planning to do correction and/or don`t care about using up some clearcoat thickness but I won`t chance it