Thanks SmoothLC!
Found some time this weekend to keep chipping away at simple things while waiting for the interior carpet to air dry.
Both of my previous LXs have had cabin filters, but I was surprised to read that some LCs didn't. Decided to remove glovebox to take a look...was greeted by the familiar cabin filter cover, but with NO filters inside. Wasn't that surprised based on previous threads I've seen, but was fortunate to not have to do the retrofit mod.
Took the trip to local parts store and asked for cabin filters for a 2000 Toyota LC. Guy punches it into the system and says, "you sure? Shows here that car doesn't have cabin filters."
I told him to change the search based on a 2000 LX470 and headed home with the filters.
Before slapping them in, I vacuumed the evap canister as thoroughly as possible (it was pretty filthy), and followed up with a few passes of a foaming cleaner. I prefer this one specifically because it shoots a narrow, viscous jet you can control and "paint" across the face of coils. Others I've used in the past are just a standard cone spray, and given the narrow "window" you've got to work with, it just gets sloppy.
After a few minutes of dwell time it started seeping out of the drain hose in the engine bay (and also reminded me to make sure to do the drain hose relocate mod to avoid constant frame dripping).
I then used a thin brush to loosen away any stubborn crud, and did my best to get my vacuum head in there. My little Milwaukee vacuum has a short and stubby head so it did a decent job of getting the lower portion of the evap coils through the blower motor location (I removed it for cleaning and removing a few leaves from it).
After all said and done, slide the cabin filters in, cassette style. First one drops, and second slides right over it, centered via the plastic rails. Don't force it if it isn't correctly aligned!