Pesachim 45: The Dregs of Chametz

Marking a (solar) year of daf yomi. || When dough gets into the cracks of your mixing bowl. Is it a kezayit's worth? Does it have value for the bowl itself? Also: When 2 half-kezayits do not make a whole kezayit - specifically in the kneading bowl. But this seems counterintuitive - and indeed the case is left unresolved (teiku). Plus - food that is not fit for human consumption, but a dog would eat it.