The hatred for and resentment of Salazar and anyone associated with him is of course old news on here, but I remain unpersuaded by such expressions and their accompanying accusations, and in this particular case I am not persuaded that supplementing with a legal, and WADA-legal, fully available to anyone, amino acid is sleazy or unethical, or cheating. There are substances that are prohibited and those that are not. L-carnitine is acceptable, so trying it is not cheating. And so what if there are a few possible side effects associated with its use -- those stated here are associated with ingesting pretty much anything, legal or not, food or not.
There are also known benefits and possible side effects training at altitude (headaches, shortness of breath, nausea). Moreover, altitude training is not available to every athlete -- depends on the resources you have. So, not everyone has the opportunity to train at altitude, but that does not make those who do so sleazy, unethical, cheaters, etc. I suppose, in this morally perfectionist world of LRC, a truly 'ethical' athlete or coach would refrain from altitude training because (a) it has known benefits, (b) it has some associated risks, and (c) not everyone has access to it.
I would like to get cheaters out of this sport, but I don't see how accusing pretty much everyone of cheating facilitates the actual identification of cheaters. It doesn't even make the "I told you so" game very interesting.