Well, there we go. Here is the Toyota's response to the question whether closing off the driver's side vent turns off the Plasmacluster system.

What do you make of what they said?

Subject
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Re: Camry Plasmacluster [Incident: 060511-000295]


Discussion Thread
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Response (Robert) - 07/26/2006 11:02 AM
Thank you for contacting Toyota Motor Sales, U.S.A., Inc.

We appreciate your interest in the Camry.

The driver's air conditioning vent does not function as a switch for the
Plasmacluster system. We do not have indication that closing the vent turns off
the Plasmacluster system. The system is not designed to redirect ions to other
vents. We apologize, but do not have additional information on the system to
address your inquiries in greater detail.

If we may be of further assistance, please <as-html><a href = ' http://toyota.custhelp.com/cgi-bin/toyota.cfg/php/enduser/std_adp.php?p_faqid=4164'TARGET=_BLANK>contact
us</a></as-html> via <as-html><a href = ' http://toyota.custhelp.com/cgi-bin/toyota.cfg/php/enduser/std_adp.php?p_faqid=164&p_created=990827420'TARGET =_BLANK>email</a></as-html>
or by calling 800-331-4331. We are available from 5 AM to 6 PM, Pacific Time,
Monday through Friday, and from 7 AM to 4 PM Saturday.

We have documented your comments at our National Headquarters under file
#200505120577.

Toyota Customer Experience

Mostly, it looks like they sidestepped the question.

Link to My Hybrid Car News Web Page

Don't you love it when the user knows more than the manufacturer? That really peeves me.

Probably the one guy that knows how it works, his "Jenglish" isn't too good. "Ah, da pwasma-cwuster, it no go off".

Two climate control systems, one inside and the other at the tailpipe.

2007 Camry Hybrid (in service June 2006)
FE: 6.77L/100km (34.8 mpg) over 37750km (23450mi)
75% city - Ave trip 20 min - 2 Winters

The Tech Manual describes how it works it fair detail.
The Plasmacluster works only when the AC is on, and it releases charged ions through the driver's vent only. You can read about Plasmacluster in more detail if you Google it- I believe it's made by Sharp and is sold in household air purifiers.

Does the "PlasmaCluster" have a dedicated fuse?
If yes, just pull the fuse to turn PC off.
J