Drawing cookies would be really tough.  I also thought about colored marbles which might be easier - although not as tasty and harder to track first in / first out. Yes, the example is not at all realistic today - since I had a diff of 20 (5 times being 100), the jar rolled through all the cookies in a few minutes.  Obviously we are putting in 47,823 trillion hashes per second (not sure how many shares / cookies that is) and the diff is 3,007,383,866,429, so the jar is much bigger and so it takes wayyyy longer to cycle through the whole jar with cookies.  As I understand it, during the 5nd may find 50 (or 500) blocks or we may get none at all during the time we are filling the cookie jar so I do not think it is related to blocks found either.  yes, this very confusing and I think this is getting into the realm of making it more confusing though....