No offence taken my friend. Speech Therapy is a proven and effective first line treatment for any speech impediment. With that said, Its effectiveness depends on other factors like age, severity and consistency of treatment. Im sorry to hear it didnt work for your son. Believe me when I say this, I have no problem believing that, as speech therapy did not do much for me either. With that said, that does not prove its not scientifically viable or useful, as demonstrated by numerous clinical trial. The same cannot be said regarding omega oil as there is no scientific consensus about their effectiveness, even though some studies suggest it could be effective. As a community we just try to stay within the bounds of scientific consensus because otherwise, as im sure you can imagine, a lot of people post ludicrous stuff and voodoo magic advice that does not do much good. At the end of the day, all that matters is that your son is doing better, whatever the reason.