Welcome to the wonderful world of DIY. Tall order. It is said, "Antidote, is the hardest flavor to duplicate". I'll give it a shot and let you know the recipe. Primarily, it is Watermelon, Apple, Spearmint, and a touch of bubblegum at the end. If I could taste and or smell it, the job would be a little easier. Bamskilicious has their own line and they have Hansen. Hansen is Chinese, the good news they are ISO9000 compliant. That means they aren't going off into left field and mixing a molecule from the sewers of Singapore, so we have a fairly stable platform to work from. I don't use Hansen's concentrates, even though they are available from ecig. I will use mostly TFA,. The larger % required are more forgiving and easier to manipulate. If you want to work on it too, I am going to start with:
Watermelon (TFA) 12%
Spearmint (MTB)** 8%
Apple (TFA) 10%
Bubble Gum (TFA)* 5%
NOTES
** I am almost out of Mt. Bakers Spearmint and have ordered TFA as a replacement. That will be different.
TFA Apple peaks @ 13%. Since note much is said about the Apple component, I'll throttle back some, but it is weak and can't compete with the Spearmint, so we need to mix it on the heavy side.
* I suspect they use the bubble gum as the sweetener and depending upon the Bubble Gum concentrate they have chosen, there will be a different flavor.
There is a starting point, with some thinking out loud, for us to start with. We won't be the only one's. There is a great guy on here that goes by HIC, he too is a mixologist with extraordinary talent and he will probably jump in, along with others. Maybe some of them have actually tried Antidote and can shed lots of light on the subject.
Eric