Dishwashing-machine powder (I'm wary of this stuff ever since it ate
pits into the bottom of a pan when left overnight in the sink)

It has its uses, but the most proper ones in my opinion involve the
use of the associated appliance. (Have you considered just tossing
the chain in with the next load of dishes? There have been reports
thatthis works...)

Yeah, I did read the thread on here about that a couple of days ago, but I
really think my parental units would go haywire if I even suggested it

and filling the bottle
with water and shaking vigorously for a while, maybe changing the
water a few times to make sure I clean out all of the cleaning
chemicals.

Counterproductive with the WS solvent. Just take the chain out, wipe
it off, let it dry for a short while, and lube it.

Yeah, I realised that rinsing with water was a bit silly a short while after
submitting the original post. Is it alright to leave it overnight to make
sure all of the WS evaporates before lubing? Or is it going to start rusting
instantaneously if left without lube...?

I will note that my former contacts at DuPont were, without exception,
less than complimentary about the various PTFE-doped lubricant
products on the retail market. PTFE is a generic term for the same
stuff as DuPont's Teflon. It does have valid applications as a
lubrication layer, but as far as the people at DuPont were concerned,
the majority of the *consumer* products on the market which
incorporated it were simple frauds. DuPont did the early work with
the stuff, they discovered it properties and usefulness, and in heir
own plants, they don't use it for a spray or oil-carried lubricant.
If the oil base that the chain lube contains is a good lube, then the
presence of the PTFE is certainly going to do no harm; the stuff's
amazingly inert at common temps. But it will *not* remain in place
between loaded surfaces without a mechanical retaining method of some
sort, so it's unlikely to do very much on a chain.

So basically I have some spray-lube in a can which may or may not work well
but the PTFE content is completely irrelevant and unlikely to make any
difference?

Thanks for your help,
Dani.