I highly recommend you do some Dungeoneering and buy the scroll of cleansing, can save you a pretty penny in the long run. It gives a 1/8 chance of making a potion twice as fast but, more importantly, it has a 1/10 chance of saving a second(or an herb if you for some reason decide to make unf pots first); It's a chance at each, not a 10% of the time.

