I get occasional spadsms, too.Usually brought on by chunky cold stuff like tater salad. I have to slow way down and make sure one bite goes down all the way before I take the next. Before I learned how to recognize it and deal with it, on several occasions I'd be eating and feel the food stack up, same mucusy stuff you describe. Then grab a glass and sort of vomit into it the food that never made it down. As you say, it's fairly disconcerting when it's going on. Fortunately, after a minute or so it goes away and i can continue as normal.