I usually dig out as much of the damaged goods as possible, avoiding damaging the interior surfaces of the vessel,(I used a wooden spatula and/or spoon) then drop in a tablespoon of powdered DISHWASHER detergent and fill the pot with boiling water. I then allow it to rest overnight. Next morning all the nasty stuff wipes out fairly easily.
What's worked for me in the past is to scrape out as much as you can. Then fill the pot to the point at which there's stuck on stuff on the sides, add baking soda, and bring the water to a boil on the stove. Let the water cool down enough to get in there w/a pair of gloves on and scrub the muck - usually lifts off pretty easily. Hope it works!
Probably. Scrape out as much as you can, then add hot water and dish soap, let it sit for a while, then scrape it again; repeat. As one of your "repeats" you can add enough water to completely cover the stuck on stuff, put it on the stove and let it simmer for a while (don't forget it this time!), then scrape and scrub it while it's still hot.
I can't tell what material that pan is, but when you get down to the last layer, Bar Keeper's Friend, applied as a paste, let sit, and the scrubbed off with a tough scrubby and/or a toothbrush can help get the last stubborn bits.