Well, doctor knows best. Or, in this case, magical talking zebra with an unparalleled knowledge of potions knows best. Either way, Joker drinks carefully from the ladle so as not to spill a single drop- never be wasteful especially with potions. Zecora's investigation he mostly ignores. She's just doing her job, after all.

Alas, as most of the other times, there's no change in his empty side. Perhaps one day, but not today.