When I was a teen, I occasionally used to find little lumps of yellowish stuff in my mouth, about the consistency of cottage cheese. They smelled nasty, kind of like poop. This hasn’t happened to me in a long time, not since college.
They seemed to come from the back of my throat, so I guess they could have come up from my stomach. Perhaps they were some kind of post-nasal phenomenon; sometimes as an adult, if I have a cold, I’ll wake up with with some phlegm stuck in the back of my throat, but that in NOT the same as the waxy stuff from my teen years.
We call them tonsil stones on this board but yep, that is what they are. We have discussed them a number of times so you should be able to search for earlier references. They are about the foulest smelling thing the body produces. I got my tonsils out as an adult and one of the benefits is that I don’t get them anymore.
Search for some threads on tonsil stones. Some people seem to be good at producing them. I am sure they would be happy to sell you one for a nominal fee. I only had a few in my life before I got my tonsils out but that was more than enough to be memorable forever.
They are some of the foulest smelling things you possibly be unlucky enough to catch a whiff of and they can be hard to remove yourself although I always found a hard prodding with chopsticks at the very back of your throat would eventually do the trick.
Some people have them and just don’t know it or don’t do anything about. It make their breath smell literally like shit except much worse somehow.