This might sound weird, but I experience the same thing. I believe it is because I swallow smoke every time I get high (yeah, I'm really bad at just inhaling/bucket..) Anyways, this is going to sound weird too, but when I can, I "regurgitate" after I smoke, and I definitely notice the after-effects of smoking. If I don't throw up, I can feel that there is certainly something wrong with my throat, but after I get out the small brown specks, I find I can clear my throat as if I have not smoked, and breathing/swallowing is much more comfortable.