Sayyidah Aishah (may Allah be pleased with her) narrates that the Messenger of Allah (peace and blessings be upon him) said: "Among the best qualities of the fasting person is using the miswak."
Others are more reliable than Mujalid, and Asim bin Ubaydullah is not strong; and Allah knows best.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الصيام / 8326