Nope, because both of the above described methods are flawed. Also, both methods are created based on assumptions of what 1 group will choose to do, which is one of the many reason why the experiment is bull sh--.
Method 1 will give you a high correlation between offering snacks, and joining the chess club, but as you have shown many times in the past, there is one fact you cannot seem to grasp.
CORRELATION DOES NOT EQUAL CAUSATION!!!
All you can say from method 1 is that there's a correlation. You dont know the causation, because you only polled the "interested group". They could be coming due to the snacks, they also could be coming due to their interest in chess.
I work in science. We deal with hypotheses. I figure out what i THINK will happen, and test it. If it works, i have results. if not, you test something else. What i dont do is make an assumption, and then base my experiment off treating the assumption like it is the truth. thats what you have done consistently throughout your assinine arguements.