5. Regular dish. Contrary to popular belief, if a dish requires teviloh, one may not use it even once and even in a casual manner before toveling it (רמ"א שם ס"ח ). Nevertheless, if one used a dish without toveling it, the food inside does not become ossur (רמ"א ססט"ז ).
6. Dish which comes with food inside. One may use a dish which comes with food inside, e.g., a bottle of wine or jar of coffee, without toveling it as long as its original contents have not been used up (שו"ת מהרי"ל דיסקין קו"א אות קל"ו, שו"ת חלקת יעקב ח"ב סי' נ"ז, הגרשז"א בשש"כ פ"ט הע' מ"א ).
7. If one wants to refill the container after it is empty, whether with the same food or different food, he must tovel it prior to using it again. Although some say this is unnecessary since the non-Jew produced it intending for it to be thrown out after its use and a Jew designated it as a kli (אג"מ יו"ד ח"ב סי' מ', או"ח ח"א סי' קכ"ב ענף ט' ), most poskim hold it requires teviloh since he did not actively do anything to designate it. Thus, he must tovel it with a brochoh (הגר"ש וואזנר , קובץ מבית לוי יו"ד עמ' קמ"ו סי"א ועוד ); some say without a brochoh (שו"ת מחזה אליהו ח"א סי' ק' אות י"ב וי"ג ).
8. As long as the wine bottle or coffee jar’s original contents have not been finished, one may put some back. E.g., one may return some kiddush wine from his cup to the bottle if it is not yet empty (גליון ח"ח 28 אות מ"ג ). Similarly, if one took too much coffee, he may put some back into the jar as long as it has not been completely finished (הגרשז"א בשש"כ שם ).
9. Coffee refills. Sometimes, stores have a sale during which one can buy a jar of coffee along with a second soft pack intended to refill the jar after it is empty. One must remember to tovel the jar prior to refilling it. He does not need to first take off the stickers on the jar since they are part of the jar and it is normal to leave them on (בגליון הבא בעזהשי"ת).
10. Disposable aluminum pans. Flimsy dishes intended for one-time use, e.g., disposable aluminum pans, do not have the status of keilim since their use is temporary and flimsy in nature. Therefore, they do not require teviloh (שו"ת מנח"י ח"ה סי' ל"ב, ח"ח סי' ס"ט ) even if one reuses them.
