I've been around these detailing forums for over 15 years now, and to my recollection the whole idea of a "drying aid" pre-dates rinseless washes (well, the mainstream use of rinseless washes...before ONR put it in the mainstream, there was QEW (quick and easy wash), which people only used during the winter in the garage when they couldn't do a conventional wash).
The idea was that a lot of swirls came when you were drying your car after a conventional wash--when there was no lubrication for the towel. So people started using QD to make the towel glide and clean up any leftover water spots (and give you some transient gloss, which some people did anyway after washing--use QD, that is). Somehow that morphed into using spray waxes and WOWA sealants as they became available. Since most rinseless washes have a decent amount of lubricity inherent in the function of the product, and you usually don't get the degree of spotting that you do during conventional wash (from rinsing parts of the car before you are done washing, and not having clean rinse water sitting on the car, only "treated" rinseless wash solution), I never really saw the need to use a drying aid with rinseless, besides, I don't really want to make my drying towels hydrophobic.
I can see ONR being used as a drying aid for a conventional wash, particularly if you've gotten some water spots during the rinse/dry. Are you sure that's not what they're talking about? On the other hand, some people may not really understand the nuance between conventional, rinseless, and waterless washing as some of us do from watching it evolve over the years, and everyone is an expert now from using Google and watching YouTube.