No, it can't be used on Maxis clothing. To recategorize Maxis clothes, write down the name of the Maxis clothing you want to recategorize in CAS debug mode, and find the Property Set for that clothes using the SimPE's resource finder. (PropertySet Search) Extract the property set, make a new file, and add the extracted resourse to the new file. Change the category as you want. You can find category value here.

A lot of creators already made various outerwear mods/clothing hiders. You can edit them to suit your needs. For example, fanseelamb's Outerwear mod adds GLS coat to Outerwear. Download the mod, and change the category in Property Set to 0x1000 (Outerwear only).