[Flyndaran]

Even if one allows significant home made chemicals, most require unusual and/or volatile precursors. That would result in quite a long time period working up to the stuff needed.
Though I love the idea of a super genius chemist's home having jars of strange materials just the other side of realism akin to the clichéd wizard's pantry.
And this many posts without once mentioning MacGyver? Much of what I remember involved realistic gadgeteering or serendipity coupled with mostly realistic chemistry.