Broomstick method tips

[3KillerBs]

Those were just the death throes, electrical impulses that happen with every death unless animal is highly tranquilized(what they do at the vet).

Yes.

And I'd like to add that the stronger spasms happen when you get the best, quickest, most thorough severing of the spinal cord and thus the fastest death.

It's disconcerting, but it's actually a good sign that you've done it correctly.