According to the manual, the plasmacluster only works from the driver's side dash vent. So I suppose if you close this vent and just use the center console vents you can stop it from working. But other than that, there is no specific on/off for plasmacluster.

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