Is this batch of sauerkraut salvageable?
My kraut doesn't always show signs of foaming, and, even though it is fermenting, it is relatively crisp. Further, 11 days is not very long. The container you use is not that important.  What is important is salt (and if you say it is "very salty" you probably have enough) and keeping the cabbage submerged. You will need to weigh it down so that all of the cabbage is under the liquid.  When you remove some with a clean utensil, what do your senses tell you?  If it feels slimy discard it.  If it smells bad, discard it. If you see fuzzy mold, you are better off starting over.  Otherwise, give it a taste.  My guess is that it is not very fermented after only a week and a half, so I would keep the experiment going.