I have not seen -every- spark out there so I can’t give a definitive answer, but the ones I have personally extinguished have been, yes.
I picture Megatron’s as spewing pure darkness though. Just a hunch.
…I am not exactly sure why a fleshling needs all of their hearts filled. My research indicates that fleshlings only have one heart, and as for what the frag I’d be filling it with…bullets sound nice.
I believe a better exchange would be you letting me out and then I, the mighty Starscream, will fill the jar with human hearts. Sounds pleasant, doesn’t it?
Seeing as I have plenty of spare time while sitting on this Primus forsaken shelf I suppose I can offer some words of wisdom in exchange for a way out of this slagging trap.
Or you could all ask the inevitable foolish questions you meatbags so love to spew and I can plot your demise.