There are no specific rules about physical cleanliness for believers in Christ. There are many instructions such as “be clean” and “cleanse your hearts” but these are all referring to spiritual cleansing. Here are two examples.
Draw near to God, and he will draw near to you. Cleanse your hands, you sinners, and purify your hearts, you double-minded. (James 4:8)
Since we have these promises, beloved, let us cleanse ourselves from every defilement of body and spirit, bringing holiness to completion in the fear of God. (2 Corinthians 7:1)
Similar examples may be found in Acts 15:9; 2 Corinthians 6:17; 2 Thessalonians 2:21; Hebrews 10:2,22; 2 Peter 1:9; 1 John 1:7-9 and Revelation 21:27.