We need to understand the reason why you want to trip the RCD to the whole house if you have an issue within a certain room and what the hazards or risks are in your set-up and use as it is, although its not the usual place to put such a E-Stop system , what is required is a risk assessment. The results of the risk assessment will go most of the way to explain the system you require to do what you need, it is always best to limit any deliberate power cuts to only the area, room, outlet or load that needs to be disconnected and it also needs to be shown that losing power through a deliberate action does not provide a greater hazard than say keeping the power on and controlling the situation like in some kinds of machinery be it industrial or benchtop.
When you crash the power at home you have to remember that this can cause other issues like electronic goods failure due to the transients that can be experienced with power failure hence the action to stop power should be as local as possible.
Getting on to the act of using a deliberate fault to action a RCD to achieve this is definately a no no, unless you use a device that has been specifically designed to do this with the use of a remote action point to it.
There are no cheap solutions around this and the real cost would be guided by the risk assessment, I assume you want to do this to prevent risk or damage to property or persons, both of these do require recognised methods to be compliant of which creating a deliberate N/E fault on a RCD is not one of them as it isn't fail safe on numerous levels.
I'll keep the thread open to allow response from the OP but if the nature of that response is not to realise after the various responses that this is not a good idea and should not under any circumstance be done as any kind of safety set-up or even as an experiment then the thread will be closed, the rcd should only be deliberately operated by recognised methods usually done in routine testing through action of the test button or the use of test equipment.
