I, too, homeschooled a child with speech difficulties. It was very hard for her to communicate with others, and it was a heartbreaking experience to see kids walk away from her because they couldn't understand what she was trying to say. I'm certain this problem would have been exacerbated in a school environment, where she would have been forced to attempt communication with many people before she was physically able to do so. Today, at eight years old, she is a popular child with no trace of speech difficulties. She is still homeschooled.
I did sample several speech programs, but none of them were particularly helpful. I researched speech irregularities, and discovered that maturity was the biggest factor for attaining clear speech. For instance, the "R" and "S" sounds are sometimes delayed in children, and are often not stabilized until seven or eight years old. By seven years old, most of my daughter's speech problems were beginning to go away, and by eight they disappeared entirely. Please visit our homeschool channel for more information on homeschooling your child. Good luck!