Bleeder resistor: switch resistance on when capacitor is powered off?
Difficult to answer without a schematic, but if you have at some point a signal that drops to -near- ground when powered down, but is high when power is on, you can use it to drive the gate of a p-mos (or the base of a pnp) which in turn controls whether current flows through your draining resistor or not. 

At the gate/base you would have a pull down resistor, so that the transistor defaults to 'on' (draining your cap).

This way negligible power is wasted during normal operation, and the cap is drained when power is off.