How many reflections of the map you've used? Umm. Well, I've used some to collect Meal components, and some to collect Queen cookies. Why is this useful?
Or, do you mean "how many DRINK ME potions you've used that have not (yet) yielded up a reflection of a map"? If so, how is it "possible to check how many to use [while wasting turns]"? I suppose we could increment a counter every time you use a DRINK ME potion and decrement it every time a reflection of a map drops, but considering that my main and my multi have each farmed 50 queen cookies, I'm not feeling much motivation...