No, this is true for the regualr ParaZapper which is 100 percent Clark in the 30 kHz mode, down to the actual resistors and capacitors.
Size also makes a difference for the ParaZapper PLUS which is also fixed resistance and follows Dr. Clark's original design, except the timing resistance and capacitance values have been changed to extend battery life.
It appears to be true for all zappers based on the 555 times but not for the CD4069 which appears to be power limited.
BTW, when do you expect to post those data sheets?