Is it permissible for a fasting person to use commercial toothpicks if he is not proficient in using a miswak?

It is permissible for a fasting person to use a siwak (tooth-cleaning twig), and there is no harm in using toothpicks. In fact, it is better to remove food debris from the mouth for fear of swallowing it. If a fasting person intentionally swallows what remains between their teeth, their fast is broken, without disagreement among the Shafi'is, Malik, Ahmad, and Abu Yusuf.