I vote we should...
Full question: Should we stop reducing to slogans like "boots on the ground" what amounts to sending people to be violently slaughtered?
I don't think 'boots on the ground' is quite the euphemism example you're looking for. As mentioned above, it's a difference in how we wage war, not one of the phrases used to dehumanize the enemy.
There are plenty of phrases used by soldiers to dehumanize the opposition, of course. And those terms are shared with the politicians calling for or gleeful about inflicting some harm to the enemy.
But i'm not sure if the phrasing is the problem. I mean, surgeons also dehumanize their patients. Seeing them as technical problems rather than people helps the doctor focus during surgery. It also protects the doctor after a patient is lost. It's a number, a statistic, not Ol' Fred, the guy who teased the nurses and bled out on the table.
Soldiers are sent to kill and basic human tendencies must be conquered in order for them to do that job. They will dehumanize the enemy, in order to win, to survive and to overcome trauma after they come back. Fighting the soldiers' use of dehumanization makes it harder for them, but the politicians are still going to send them in.
You need to get the politicians to stop sending people into war zones, then dehumanizing phrases are not an issue.