I have had this problem! It appears that it is a film from the wine that becomes difficult to remove. Soak it in warm vinegar then apply some of this polish and scrub firmly with a brush.
Lecruset sell a very good cleaner for their cast iron range of dishes. Le Creuset ecological cleaner and protector for enamelled cast iron cooking utensils, 250 ml, 71039 https://www.amazon.co.uk/dp/B01AXZ6E8I/ref=cm_sw_r_apan_glt_i_FM1P7H4CP6F1TA470KFR
Leave that to soak on it for 30 mins and scrub the life out of it, rinse off and wash as normal, it will look brand new.
Le Creuset sells a product for this purpose. Used it years ago and thought it worked well. I’ve grown to enjoy the look of burned on stuff so I stopped, but worth a try for a second hand purchase.
Le Creuset ECC251 Enameled Cast Iron Cookware Cleaner, 8.45 oz https://www.amazon.com/dp/B01AXZ6E8I/ref=cm_sw_r_cp_api_glt_i_NFYR1DH4C7YFSX3Z621T
> he cooked the enamel right off.
That's really not possible. Like others have suggested, heat baking soda and water in it. Might need a few tries, but it will work. Also Le Creuset have thier cast iron cleaner... pricy, but will work.
Here is the link...
https://www.amazon.co.uk/Creuset-Ecological-Protector-enameled-cookware/dp/B01AXZ6E8I
Lastly, don't worry, dutch oven is fine. Also head to r/castiron, that is much bigger community and there are plenty of people who have been in similar situation as you.
Yes, but I'm not. Oh whale :(
Use this along with a light sponge. It works wonders on enameled iron. No need to be aggressive when cleaning enamel
Le Creuset sells a cream cleanser with a mild abrasive (similar to what is in ceramic/glass cooktop cleaner or liquid barkeepers friend). It does a really nice job of cleaning the muck and marks off.
https://www.amazon.com/Creuset-Enameled-Cast-Cookware-Cleaner/dp/B01AXZ6E8I
Le Creuset makes a special cleaner that will take this off. Its designed specifically for enamel and work like a charm. I use it on my le Creuset every 6-12 months or when build up get bad.
The Le Creuset enameled cast iron cleaner works really well
Le Creuset ECC251 Enameled Cast Iron Cookware Cleaner, 8.45 oz https://www.amazon.com/dp/B01AXZ6E8I/ref=cm_sw_r_cp_api_glt_fabc_04583M87RCFDE7C72ZMX?_encoding=UTF8&psc=1
You can also get this
Le Creuset ECC251 Enameled Cast Iron Cookware Cleaner, 8.45 oz https://www.amazon.com/dp/B01AXZ6E8I/ref=cm_sw_r_cp_apip_Pqk2N5AZIIOdL
It is possible to clean up the inside of that cocotte. Le Creuset makes an enamelled cast iron cleaner but it's expensive. I use the Lagostina version on my Le Creuset cookware. It works well and is cheaper. But try boiling some baking soda in the cocotte first.