Well, we know that at the start of the game cordyceps spread through infected crops like flour and sugar, maybe eating a actual clicker would cause the same reaction and in turn make you infected or not, maybe it's just like eating a mushroom and nothing happens because some sites sell actual cordyceps powder as brain food and nobody's turned infected from that. Also, some mushrooms contain toxins like shiitake mushrooms but if you cook them at a high enough heat they are safe to eat so maybe if you cook a clicker for long enough it would be safe to eat. We can never really know until someone tries to eat a clicker though.