Y'all are amateurs. The more cutting, cooking, and chemicalling you do, the more likely you are to leave trace evidence on yourself, and in a trail all the way to wherever you disposed of the body. Dennis Nilsen managed to rack up double digits, but still got caught because his careful cutting up and dumping down the toilet with lime and other chemicals didn't work- the plumbing overflowed. Boiling bodies down is part of what got Jeffery Dahmer caught- human beings stink when they are boiled down to the bones. 2 tiny teeth fragments and a few strands of hair put Richard Crafts away for the murder and woodchipper-disposal of his wife.
If you want to kill somebody and get away with it, look at the people who got away with it: Jack the Ripper did a fine and dandy job by knowing the neighhorhood well, killing his victims, and just leaving them there. Ted Bundy wouldn't have been caught if he hadn't let Carol da Ronch escape his VW bug: grab your victim, render him unconscious, and transport him to a spot deep in the woods to finish the job, leaving the evidence there. The Green River Killer excelled at body disposal: choose an openly accessible, but too large to patrol all the time, area and dump the bodies there. The key is to kill a stranger, and have only *one* crime scene: murder and disposal in approximately the same place. When you have secondary and tertiary crime scenes, you're just creating more places to leave evidence.