Oh boy, where to start.
Brandy, you can make your own yogurt without even hardly trying. And yogurt is a lot like sourdough starter, in that you can use the yogurt you've already got to make more yogurt.
Here's a link for you on how to make your own:
Make YogurtAnd now to address the apparent skepticism for both applying and using yogurt to help with Yeast infections.
First off, it's important to note a few things that every student of science (ie - all of us) ought to know about their body. We have millions upon millions of bacteria in our bodies. In fact, if I were to make every part of you invisible, except for the bacteria on and in your body, the idea is that you would still be recognizable. That's how much bacteria is on and in you. AND THEY ARE MOSTLY GOOD BACTERIA.
It is also important to note that species of bacteria are a lot like communities of people. Imagine, if you will, that your body is, say, the United States. Different parts of your body constitute different areas of the country, and different types of bacteria like to grow in those different areas. Some bacteria prefer the warm, moist environments of our insides, and some prefer the dry, windy, desiccated landscape of our skin. Some prefer our mucus membranes, and some prefer the most nutrient rich areas of our bodies, like the GI system, intestines, the urethra, our reproductive areas, etc.
You know how when human communities get really tight? Small towns are the best instance of this. EVERYBODY knows when the new guy moves into town. And if he's bad news, he gets tossed out if the community can manage it. Well bacteria is EXACTLY the same way. Sometimes, they let newcomers hang out, because they provide something good for the bacteria (like the way humans let some dogs hang around their community, as well as cows, horses, sheep, etc.). Sometimes, though, the recognize a threat, and they do their best to eliminate it. They do this in a couple of ways. They can out compete the bad bacteria, and shove it out of town by not allowing it any real estate. Or they can get nasty, and poison the bacteria, if the good bacteria has the means to do that. Or they can out compete the bad bacteria by starving it. Think of how we might shove somebody out of town if we had no morals. That's how bacteria work. It's actually really fun to watch. but, er.. that's another story.
First - I'm not a doctor. I'm a pre-veterinary medicine student - and therefore only know what I know based on classes that I have shared with pre-med students. These suggestions are based on my limited (ie - not Master's or PhD level) knowledge of Biology and of the human body.
So saying that the application of yogurt culture (good bacteria) by either actual application, or by consumption is a good thing is absolutely correct. It's like bringing in the police force. Consumption of the yogurt is like bringing in the police force over the highways, and allowing them to sit in traffic for a while. In other words, it takes a lot longer. But it works just the same. Application of the yogurt is like giving the police a bunch of 4X4s, and telling them to have fun.

They will go crazy, and do everything in their power to eliminate the problem.
What worries me is that you are having this issue so often. It says one of a couple of things, and each of them really need to be addressed by you in whatever way you have available. The first of which, is that any medications that you are taking may be hurting the chances of your good bacteria to thrive. IF that's the case, I'm not suggesting that you get off of your meds. But I do suggest that you start eating yogurt in your diet more often. Boosting your body's ability to kick the asses of bad bacteria is a very good idea for you if you have this issue often.
Also, washing too much down there can cause this problem. I'm NOT saying don't wash down there. I'm saying use something a little less industrial, yes?

Like unscented Dove body wash. Respect the poon, yo. She deserves something more gentle than the microdermabrasion scrub you use on your toes. Which brings up another point. Don't use a washcloth down there. Washclothes have mold on them from the day you put them in the shower. They also have all of the bacteria that didn't die when you scrubbed it off of your skin. Applying that mold, and those bacteria to your pretty places is not a great idea. Use your hands, after you've washed them properly.
Also, I've heard that different kinds of water (soft or hard) can cause this problem too. I'm not familiar with how to fix that problem, but it is something to keep in mind.
Again, I'm not a doctor. I'm only suggesting what I believe to be correct. If I'm wrong, don't hesitate to tell me so. And if you have any questions, I'm neither bothered by the subject (obviously), nor do I think that any questions are "too stupid" to be asked. And I'll do my best to provide backup for what I'm saying if it's asked of me.