a 66% het is the offspring of a pair of 100% hets bred together. If you breed a visual albino to a het the offspring will be 100% hets and visual albinos. I would say if you want to get into albinos the prices are low enough to buy maybe a visual male and one or two 100% hets from a reputable breeder. But for some of the more expensive recessive morphs such as clowns hets can be a cheaper way to get in the game and give yourself the chance of making a visual of your own.
hope this helps