Honestly, for me this has been something I see in this age range (really until closer to 5). I have a few kids past this age & have watched others & it takes some time to coordinate wiping and paper usage. I'd have to say I've just stuck to supervising. They don't want it to get onto their hand (and you don't either) so they can tend to overdo it. Also, if they have to wipe many times, they lack the ability to know they need to flush it now, and then wipe more, in order to avoid ever over filling with paper.
I do know there are flushable wipes you can use & those may result in less paper usage since a damp wipe often takes less attempts, but you should be aware those are not at all friendly to sewer systems & water treatment plants hate them. I know they say they are flushable, but apparently they do in fact cost these facilities a fair amount on removal (clogs their systems) and they pay to have it hauled elsewhere & dumped. So since I learned that in researching them, we haven't tried that way. I have told kids they are free to use the normal baby wipes if they then put it in the trash & I take the bathroom trash out daily (it also has diapers in it though here, so it may be a more feasible system in my case).