Is it permissible for a fasting person to put a stone in his mouth?

Question : A smooth stone is placed in the mouth to collect saliva and swallow it.

Answer : No, this is perhaps if he puts the stone in his mouth and it has a taste, then he collects the saliva on it and swallows his saliva with the taste in it. But if it has no taste at all, there is nothing wrong with it. However, I think a person can collect his saliva without putting a stone in his mouth.