set client variable purge interval with adminapi?

We have a cfml page that sets up configuration for new servers using the adminapi package.  I'm able to find methods for setting almost every config option I need, except for the purge interval for client variables.  It defaults to 1 hour 7 minutes; I want to set it longer.  Note that I am not talking about the purge timeout, which defaults to 90 days, I'm looking for a way to set the purge interval using adminapi. Any suggestions?