Dr Manocha explains the value of sham meditation in this excerpt from his thesis.
“The fact that some meditation techniques elicit detectable effects when compared to sham procedures while others do not implies that some meditation techniques may not have specific effects whereas others may well have such effects. This logically suggests the possibility that the genre is not homogenous and that the use of meditation versus sham studies offers a method by which specifically effective techniques may be separated from those that are not.”
More information on Dr Manocha’s thesis can be found here.