I have kefir grains, which I acquired from Gem Cultures. The grains are actual colonies of BENEFICAL yeasts and lactobacteria living together in a symbiotic relationship. Nothing could be easier, you feed the grains by adding milk, twelve hours or so later, they reward your generosity with kefir. Hey, I'm in a symbotic relationship along with the yeasts and the latobacteria!! In a way having the grains is like having a house plant. You have to feed, and tend to, the kefir grains or they will die. It is interesting to watch them feed, grow, and multiply. I understand that the grains will keep in a refrigerator for up to a month without tending. I'll be gifting several of my friends with my excess kefir grains. That way, if I ever lose my grains, they can return the favor.
The packaged product may be more convenient for some. It seems to be a case of personal preference. Home fermented kefir from either souce is better than none. I am not aware of any research that has been done specifically on inulin (FOS) and its' potential effect on candida overgrowth. Perhaps I am overcautious, but I am avoiding ANY fermented dairy products with added inulin. There are enough unknowns when fighting a candida overgrowth without adding another one to the mix.