haha ...sorry that sucks - but I've been there with fiberglass and it blows. As for bondo get the true bondo spreaders and match the mix to the color of the spreader - works like a champ.
You can try using MEKP hardener that's used for resins. It can't really mix with bondo which is why it's not used, but the principle is still the same - it'll create heat to harden the bondo spread.
You might just want to scrape off all the unmixed portion and reapply a good layer. That's what I would do - otherwise who knows how well this ghetto mix will cure.