There is a product called Frombys furniture refinisher you use steel wool pads 4ot and pour refinisher into a stainless bowl it evaporates quickly so use a little at a time. It desolves the finish .follow the steps ,clean the wood wit denatured alcohol.ten either restain or my favorite ..use low luster tong oil. Any good hardware store carries this product. Read instructions and ask a knowledgeable sales person.
Years ago I used a little bit of veg oil and cigarette ashes to take rings off of a cherry dining room table.
Was the the only thing that worked for me.
Make almost like a loose paste and let soak on table. 20 min or so. The work into the ring. Wipe clean Repeat.
toothpaste, not the gel variety, also works very well. Just rub a small amount over the water spot with a soft cloth and wipe away.
I tried everything then I saw it on Hometalk. Put a lightly dampened cloth on top on the stain & using a hot iron go back & forth. My horrible stains went away & then I sold the table.