I saw something about doing a cheek swab and finding a live sperm in someones petri dish. is this possible? how long would the sperm survive?

Does not add up: You may wish to restate your question as the two statements do not seem to add up. Sperm can stay alive, after being deposited in a woman, for up to a week. For good health - Have a diet rich in fresh vegetables, fruits, whole grains, milk and milk products, nuts, beans, legumes, lentils and small amounts of lean meats. Avoid saturated fats. Drink enough water daily, so that your urine is mostly colorless. Exercise at least 150 minutes/week and increase the intensity of exercise gradually. Do not use tobacco, alcohol, weed or street drugs in any form. Practice safe sex, if you have sex. Get HPV vaccine, if you are under 27 years of age.