The CLEARMYBOX command is entered as a keyword search using the normal DirecTV search function. It has an optional numeric argument that limits what is cleared. The space between CLEARMYBOX and the number is optional.
KEYWORD
ACTION
CLEARMYBOX
Clears APG, DRM, PLUGINS, and KEYWORDS plus reboots the box
CLEARMYBOX 1
Clears all of APG and reboots box
CLEARMYBOX 2
Clears APG and PLUGINS plus reboots box
CLEARMYBOX 4
Clears APG and KEYWORDS plus reboots box
CLEARMYBOX 8
Clears DRM and reboots box
APG = Advanced Program Guide
DRM = Digital Rights Management
PLUGINS = Software apps added to the FW image, usually some time after the download.
KEYWORDS = All options you have set via a keyword search.