It seems to me that one reason many States went to lethal injection was to make the execution "less traumatic", not only to the person being executed, but to any people viewing the procedure.
I could argue with reasons both for and against turning executions into gory spectacles again, or eliminating them altogether. But what I haven't seen are many suggestions where there is any "return" to society or the victims of whatever crime was committed that warranted the death penalty.
What I would suggest is that the one being executed be given a choice, assuming that they were otherwise healthy, to become an organ donor, and be "medically parted out" as the means of execution. This also has the advantage that recipients can be lined up in advance, and be ready to receive these organs immediately, in their optimal condition.
At the very least, this also suggests another method of execution, which is simply bleeding them to death. No more painful than inserting the needle for lethal injections, just let the flow go the other way until they pass out and die of blood loss. Use an artery rather than a vein for faster draining if need be.
No expensive equipment or chemicals, but if you do want to add blood thinners, just give them doses of aspirin in the days before.
Yes, I expect any such suggestion to cause a ruckus, but note that I specified that the one being executed be "given the option" to do this.