I think it took me about 5 months of constantly doing digs on Kalimdor to get them to reset in Uldum. I don’t know how many jars it took though. I just know I had Uldum memorized and did not have to open the map to find places after awhile. I had a friend who gave up looking for the recipe and just bought the mount on the AH before I started playing. I have more patience lol I still need the bug mount though so I may have to go back for round 2 
EDIT: Looks like I’ve completed 6 jars. Not sure if any came after I got the recipe (perhaps 1 as I did a few sites and traded in the crates for pieces after I had it). I think for me it was getting the jar to pop up in 1st place that took the most time.