I wasn't aware the speechless code was taught in PPL training, so I tend to say (when handling civilian traffic) 'use callsign speechless X (unless I know who it is of course!)answer my questions one click for yes etc... do you understand?' If I'm pretty certain it's a military aircraft, telling how many clicks to use is superfluous 'cos it's a standard and well practiced part of the military flying/training syllabus. If you encounter a further problem after establishing two way contact, the procedure is to click '_.._'; the controller should then use the 'HEFOE' code to question you as to what this is, where HEFOE stands for:
Hydraulics
Electrics
Fuel
Oxygen
Engine
By using this sequence the controller finds out what your problem might be!
TDM practices the speechless code with us occasionally, so if you get to fly with him, get him to demonstrate!!