Heh heh, a big part of every maintenance wash is doing such stuff...the grille on the MPV used to take me over 20 min. every wash, and that was working as fast as I could.
For maintenance washes, I use BHBs for the initial work (long bristles that`ll get in there effectively), but *always* have to follow up with swabs or MF-on-stick to really get things clean. I`ve never *once* done a pass/two with the BHBs/mitts/etc. and gotten things clean enough that my swabs didn`t come up soiled. Bit of a PIA, takes a lot of time but goes much quicker when I have them sealed/LSPed (which *does* take a lot of time, and I don`t mean just a half-hour).
How do you guys get a uniform application with the sprays? Do you go back with swabs/etc.? I simply must do every surface/seam individually with a swab/etc. or it doesn`t turn out right...I use a spritz of Drying Aid/UQW every wash, but still have to get in every nook and cranny with something.