We made a wit on Monday. We batch sparge in a rubbermaid cooler with a false bottom. The moment the valve on the mash tun was opened - STUCK. Immediately! Tried cutting the grain, scraping the false bottom with a long spoon, blowing back through the valve, stirring the mash, nothing would get it past a slow trickle. Frustration all around, wife was swearing like a sailor, it was epic. Finally, I stuck my keg dip tube brush up through the drain hose and through the valve. - THIS got it going, though I had to keep reaming it out to keep the line clear. So about two hours later than planned, we had wort to boil.
A few hours later when cleaning, I saw the problem. The hose that connects the false bottom to the valve came disconnected, so we were just draining through the valve.
It's pretty hazy, looks like fermenting milk right now.