Sayyiduna Umar (may Allah be pleased with him) narrates from the Prophet (peace and blessings be upon him) that the Prophet (peace and blessings be upon him) said: "When one of you comes to his wife and wishes to return, let him wash his private part."
This is more correct, though Layth bin Abi Sulaym is not used as evidence, and the hadith of Abu Sa'id suffices. A hadith has also been narrated about taking a ritual bath in between, but it is not strong.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب النكاح / 14090