Many people will purchase the pottery as a unique display or art piece but some will want to use them as functional dishware with food.
As you may have noticed, the piece you purchased is glazed where food or drink will be placed but the outside or "no-food" area can be partially glazed or not glazed at all.
Nothing unusual, my work is really based on centuries-old techniques and aren't always prepared for dishwashers or microwaves. Some wild clays must be fired at lower temperature than "commercial" clays and the unglazed parts may still absorb water.
Thus mindfulness and "love" is required. Take special care of placing food in the glazed area only and practice good hygiene by keeping food away for the unglazed part(s).
To maintain the condition and quality of your piece as well as longevity, hand-washing with a non abrasive cloth or soft sponge in warm soapy water is recommended. For example, if you have a bowl, clean gently the glazed area inside and try to avoid introducing food or liquid in the unglazed parts.
Don't place your piece in extreme hot or cold environments such as an oven or freezer, as this could cause thermal shock and breakage.
Sometimes accidents happen. If non-glazed areas have been in contact with food (sauce, soup, and so on.), you may want to clean then pasteurize your pottery before using it again in the future.
My technique is to place the item in a pan of water, bring the item to a gentle boil over low flame then simmer for 15 minutes then remove and cool to room temperature. Make sure the pottery it thoroughly dried. Here in Southern California it's super easy, I simply place the pottery in a sunny area of the kitchen or even outside.
Handmade pottery can develop mildew if not kept dry, it's rare but it can happen with any handmade pottery (not just my pieces) and you have to be more careful especially in humid weather or environment.
In such cases, soak the piece overnight in a sanitizing solution made up of 1 tablespoon of unscented chlorine bleach + 1 gallon of cool water (hot water stops bleach from sanitizing). Remove dishes and allow to completely air dry. Use gloves or utensils to remove dishes from the solution.