Assuming the Swizzlestick isn't broken, then go with the double dip.
If it is, then you have to go single. Make sure you get the lollipop to sherbet ratio correct, though - you don't want to end up with loads of sherbet at the end and nothing to eat it with. Likewise, you may not want to get stuck with the lolly and nothing to go with it. If necessary, use the lolly as a shovel to move large quantities of sherbet into your mouth.
Good luck with it all, whatever you decide.