"So you must live up to the rules and regulations of brahminical life. First and foremost is cleanliness. In your country they have so many filthy habits. For example, they don't wash after eating. A brahmana does not do like that. If he did so in India, he would be highly criticized. So even if you eat a little, still you must wash immediately. And the place that you eat at must be washed off immediately also. In this way.
A brahmana's name is suci, or one who is clean. In the toilet room wash with water and wash your hands with soap. Then wash feet, face and mouth. Your cloth must be washed daily, especially any cloth used to sleep in. In the kitchen also, things should be kept spotless and cooking should only be done by brahmanas; others may assist. That is the same procedure followed with Deity worship. So these are some of the points to note in Brahminical life. Keep yourself clean outside by bathing, etc. and clean inside by chanting Hare Krishna Mantra. Go on in this way and your rapid advancement in Krishna Consciousness will be certain."
Srila Prabhupada Letter to Laksmi narayana, 07-08-71
Cleanliness is next to Godliness. One of the most important aspects to be considered when cooking for the pleasure of the Lord is cleanliness. All things must be kept fully clean and organized, including the kitchen, equipment and utensils, and the persons who are cooking and assisting.
One should always prepare for kitchen service by first performing a complete personal cleansing. In the "Hari-bhakti-vilasa", Gopala Bhatta Goswami has explicitly described the rules of Deity worship, including protocol for the preparation of foodstuffs for the Lord. One should first pass urine and stool, shave, brush the teeth and rinse the mouth, all of which are considered to be contaminated activities. Next, one must fully bathe, chant the proper mantras, and put on clean Vaisnava clothing and tilak before entering the kitchen.
All effort should be made to maintain an atmosphere of cleanliness during the cooking process. If one is called out of the kitchen, or gets involved in some other activity while in the midst of cooking, always wash the hands thoroughly before resuming the cooking activities. After cooking and making the offering, one may change into clean clothing while the Lord is eating.
"But you do not know cleanliness, although you are..., that is because your, your cleanliness is with machine. And without machine, you cannot keep clean. Why not this broomstick is sufficient? If in India machine is not available, you cannot be clean? Keep everything cleansed--utensils, plates, teeth, hands, feet. Use sufficient water. There will be no (indistinct). Dirty things should be removed, and cleansed inside and outside. Inside cleansed: simply Krsna consciousness, always thinking of Krsna. That is inside clean. And outside, that is also required. You cannot neglect, because outside unclean means inside also you'll see unclean. If you keep both sides clean, then you will be healthy inside and outside. Srnvatam sva-kathah krsna punya-sravana-kirtanah hrdy antah stho hy abhadrani. Abhadrani, all inauspicious things, that will be cleaned. They should be washed. To become sacred thread means he must be suci. Satya samah damah saucam, saucam. One must be very clean. That is brahminism. Not simply having a sacred thread: "Prabhupada, give me sacred thread, sacred thread, sacred thread," everybody. You have got sacred thread, that is certificate, but what is your saucam? Cleanliness. The brahmana's name is suci. He is always cleansed. Everyone will see, and he'll immediately feel how cleansed he is. What is the difficulty? God has given sufficient water. For cleanliness you simply require water, that's all. No antiseptic bottle--Dettol, this, that, so many. You are manufacturing so many rascal things, but ultimately unclean. Ultimately unclean. But by God's arrangement, by Krsna's arrangement, simple..."
Srila Prabhupada Room Conversation, 12-11-71, Delhi
Bhaktivedanta Book Trust. HDG A.C. Bhaktivedanta Swami Srila Prabhupada.