It takes about 10 minutes to dissolve a Jolly Rancher in your mouth.
When you put a Jolly Rancher Candy in your mouth your saliva begins dissolving the Jolly Rancher and within 10 minutes and sometimes less the Jolly Rancher should be dissolved fully.
Of course if you chew on the Jolly Rancher and break it up in your mouth then the Jolly Rancher may dissolve in your mouth in as little as a few minutes.
But to dissolve a full Jolly Rancher in your mouth takes at least 5 to 10 minutes.
From my experience it takes me 10 minutes to fully dissolve a Jolly Rancher in my mouth unless I chew it and break it up.
If I chew and break the Jolly Rancher up in my mouth then the Jolly Rancher dissolves within a few minutes.
If you want to dissolve Jolly Ranchers in water it takes around 3 hours but in your mouth the Jolly Rancher candy dissolves much quicker.