Alot of the flavorings at the grocery stores are not very strong,and they usually have alot of stuff you dont want in your lungs in them,like xanthun gum,caramel color,sugar,etc.,if your just looking to add flavor to your juices,check out the diy section.There are alot of suppliers that sell good flavors,and you can get them pretty cheap.I
buy 8ml bottles of flavors for $1.50 and these are very strong concentrated flavorings,so 8ml goes a long way.