i dunno i've been using ONR for a few years now. i was a die hard "traditional wash" guy until talking with Dr. G and hearing how the chemistry works for ONR and later, Opti-Clean. i think traditional washes are more thorough but not necessarily more safe. does anyone really think i'm jeopardizing my finish using the new tech stuff? i don't, and i'll tell you why.
i use both ONR and Opti-Clean, as prescribed, without hesitation. i have washed vehicles of my own and others countless times, both coated and non-coated, and have yet to see any marring from such. i dry my cars inside under the same lights i correct with and nothing shows up. when i first started using the new school technology i'd light up the sides with halogens here and there and same deal - no marring.
for rinseless washes, i will sometimes pre-rinse...i will also at times pre-treat lower panels and wheels with Opti-Clean or ONR wash dilution in a spray bottle...i will many times spray OID at 4:1 on the panel before i dry...but i have also done straight ONR and OOC washes just like the label dictates. no issues.
if you feel uncomfortable with pre-treating, using two buckets and changing wash media often...i don't know what to tell you. that process is a really easy way to break into rinseless and as you get used to it you'll see it works perfectly fine. hey, make the solution a little richer if that is what you want. pre-treat liberally. do whatever you need to do but don't blow off the technology. it works. i and others can assure you of that. you just have to do it right and be careful.
i like how traditional washing gets into the nooks and crannies of things and blasts/floats stuff away that rinseless washes can't...because there is a lack of water streams (unless you use a bottle to assist)...but that doesn't mean you can't use rinseless and waterless washes in-between and when the hard to reach places that require a stream of water get too dirty, then do a traditional. undercar, cleaning brake calipers with a brush, lug holes, windshield cowls, etc. these things sometimes need water streaming to be cleaned effectively. but i dunno, i see no issue whatsoever with any of these types of products, at least the stuff that Optimum puts out. i haven't used the others except the Turtle Rinse Free and it works like a hybrid of ONR and ONRWW which is obviously a plus in my book.