My wife found this neat stoneware jug and we want to keep it but it has this thick brown gooey gunk inside it. We tried dish soap but it wont cut it. What would you use to get rid of this without hurting the jug. I have no idea what it is and the jug has no marking on it.
I bought a five gallon green colored glass bottle with a gazillion bubbles in it along with some kind of goop in it as what you have described a good many years ago , I used to hear that stuff called sheep dip back then , had the same sort of smell to it . Anyway tried all kinds of solutions to get it out with no success . I finally went to the concrete plant here in town and was able to get them to sell me a bucket of sand . I brought it home and filled that bottle about half way full along with some water . That sand was quite heavy . Sealed the neck good so there would be no spillage and rolled that bottle back and forth across my living room floor for what seemed two hours . It took a good while but the sand finally worked every bit of that gunk off the glass , and it was quite thick in places . Ended up with a beauty of a bottle . I guess that was thirty years or more ago . If you try it , I hope you have the same reslts that I did .