r_cleardecals
From Valve Developer Community
Note:Command parameters are described inside the < and > characters.Syntax: r_cleardecals <permanent>
Permanent is an omittable boolean argument which specifies whether or not to clear permanent decals as well (i.e. infodecals).
There are no available engine hooks for executing this command,
so the best way to execute it on a client is using engine->ClientCommand.
