just got 3 lab colors i ordered. from brambleberry and i guess they need to be diluted in 160 degree water??? i found their directions to be confusing, says you can either add them to 8 oz of water or use undiluted but i don't see how much you should add undiluted to the soap? just a drop or two?? which way comes out better, using them diluted or undiluted? if you dilute them, what is best to store them in? glass? thx!!