Accumulator's broken record: I don't know how anybody can touch anything like plastic lenses or paint with a tootbrush without marring it

Whenever I tried this, even with *very* soft ones (the "extra soft" models that are well used and feel OK), a quick look under good lighting with a little magnification showed marring, and I was being so gentle that I didn't even get the wax off. And yeah, I've lubricated the brush/lens with shampoo, QD, you name it. Even BHBs (and horse hair) can mar if you "scrub" with them. Light, "micro" marring perhaps, but the end result is an imperfect surface that refracts light, rather than reflecting it. Then you gotta polish them, which can start the whole thing all over again unless you get all the polish off.
To remove the residue, I use sharpened wooden sticks (toothpicks/swab sticks) and cotton wadding (from the Q-tips or womens makeup balls), with Meg's #34 or something similar. Use the wooden stick to work the cotton so that only the cotton actually touches the lens. Doing this under magnification can be a big help and it can take quite a while.
Or just use something like a plastic cleaner/polish, Pinnacle PCL, or AIO with a MF, and use it sparingly enough that you doesn't leave any behind in the lettering. A very plush MF helps get into the tight corners of the lettering.
Clay can work too.
Heh heh, then redo them with something that doesn't leave so much residue, like UPP or KSG.
I like the Wurth Rubber Care, but I don't use it for this job.