Clear job queue on IDRAC6 firmware version 2.90, Lifecycle controller firmware 1.6.5.12?

From OME I am unable to apply some firmware updates to a Dell R610.  My iDRAC6 is firmware version 2.90 (Build 04) and my Lifecycle Controller Firmware is 1.6.5.12.  I have attempted to run the following command from powershell (per the advice of many articles I've searched):

winrm invoke DeleteJobQueue cimv2/root/dcim/DCIM_JobService?CreationClassName=DCIM_JobService+Name=JobService+SystemName=Idrac+SystemCreationClassName=DCIM_ComputerSystem @{JobID="JID_ "} -u: -p: -r:https:// /wsman:443 -SkipCNCheck -SkipCACheck  -auth:basic -encoding:utf-8

but no matter what I do, and I've tried several iterations of this command in different orders and with different sets of quotes, I cannot delete a single job or delete all jobs (with JID_CLEARALL).  The output I get is:

"Error: Invalid use of command line.  Type "winrm -?" for help." 

If I run the following, I DO get the list of failed jobs:

winrm e cimv2/root/dcim/DCIM_LifecycleJob -u:root -p: -r:https:// /wsman -skipCNCheck -SkipCACheck -encoding:utf-8 -a:basic

So, I'm stumped.  I believe winrm is working, but I suspect an API has changed since all the documentation to the clearall command were written and the command as it is written no longer works.  Any assistance would be appreciated.