violent during calm down

Nicholeen,
When my children are on calm down spot for being out of instructional control, they have said mean things. examples: I hate you, i hope you die, you are ugly, ect. My son also intentionally scratched his face and head butted me in the face while on calm down spot. i have been addressing these actions once they are calm in the correction, and practice part but my husband thinks that they are not learning that these are severe infractions need to stop. What should my thinking be during and after these episodes? i really do not want to engage in power struggles or manipulate through fear/bully tacks for "severe infractions". i feel like our family needs to be all in with our new skills and TSG and not still relay on our prior dysfunctional parenting strategies. how do i tighten up on my skills in this situation? Thank you!