My first subject was doing quite well with 344 licks when he started to complain that his tongue was starting to burn. Not terribly concerned with the subjects discomfort, I urged him to continue for the sake of my winning PEZ. After about the 400th lick I observed my subject staring blankly at the wall with the Tootsie Pop dangling from the tip of his tongue. When I asked him if there was a problem he said "thy thung hurth, these thop etherament". After I snatched the Pop from his tongue I inspected his tongue to see what he was complaining about. After closer inspection, I allowed the subject to leave with the $5 I promised him.
After his 145th lick, my second subject told me that the Pop was starting to taste terrible. He pulled out the Pop and gave it to me. I studied it for a minute and realized that I had accidentally had given him the failed Rogaine Restore Pop, for men on the go.
After two failed attempts to resolve this question, the outcome of my third test convinced me that Tootsie Roll said it best when they said "The world may never know".