Code:
on *:TEXT:!idle *:#: { 
  if ($2 == on) idlemsg on /wa
  if ($2 == off) idlemsg off
}

alias idlemsg {
  if ($1 == on) { .timeridlemsg 0 5 $$2- }
  if ($1 == off) { .timeridlemsg off }
}


Remotely:
Triggers:
!idle on - Turns it on
!idle off - Turns it off

From your client:

/idle on Commands.

Example: /idle on amsg Moooo!

/idle off.

-Andy