Can't help you on the wax & wicks, use paraffin but I can give you my opinion on double wicking for a fundraiser! I used to use the apothecary jars and I hot glue my wicks. Well, on really large fundraisers by the time I double wicked the jars, this was after putting them on template to get wicks even, then I use the bars to hold the wicks-thus 2 bars per jar. Well, I was totally worn out just from wicking and it is so time consuming! I finally told fundraisers no more apothecary jars, only jars that are single wicked and they had no problem with that. Just my "sage" advice. haha