Just keep in mind that it may have a shelf life, due to the acetone evaporating away over time (leave a small bowl of acetone out sometime and see how fast it vanishes). Although I've used this DIY mix, I can only say that it doesn't work any worse than any of the other penetrating oils I've tried -- and it costs a lot less. Overall, though, I had only limited success any of the penetrating oil (and WD40 is useless). Fasteners that have finally been coaxed free using an impact tool showed very (very) little oil penetration below the surface, even after repeated applications and having sat for days beforehand. I like heat (controlled) and impact (also controlled).
That's just my experience, though. Your results may vary.