I used to make a lot of candles - I never used jars but old drinking glasses, or the proper rubber moulds.
If you are making it in a jar you don't need to turn it out,and I've never sprayed the surface with anything.
I used string wicks and I would tie the top end round a skewer so it balanced across the top of the candlepot while the wax was setting.
One word of advice: if you have lots of colours, don't melt them all in the same pan, you end up with a nasty sludge colour! Rather do all red, or all blue, etc., and make stripes across a number of containers.
Good luck - and do watch out - hot wax burns, and catches fire on the stove!