Molasses is rubbish, it does not really do anything directly for your plant, they may help the soil microbes slightly, but if you want to do something that will really help, give your plants humic acid, fulvic acid or amino acids - all are organic and will be 10,000 times more beneficial than sugar water or coconut juice.
Even better if you give all three and yes, they can all be used in coco coir, soil or hydro.
Hope this helps, Organoman.