Involved in the final steps of cholesterol and steroid degradation. Opens the last steroid ring of cholesterol by catalyzing the hydrolysis of (3E)-2-(2-carboxylatoethyl)-3-methyl-6-oxocyclohex-1-ene-1-carboxyl-CoA (COCHEA-CoA) to 6-methyl-3,7-dioxodecanedioyl-CoA (MeDODA-CoA)