Don’t kid yourself, if Hitler had figured out a way to use gas without getting payback in kind, he’d have used it. He didn’t find anything “abhorrent” unless it was his neck on the line. IOW, a typical sociopath coward.
It is true that Hitler himself swore off the use by his military of these weapons, and just for the reason stated that he had been injured; on a side note he won the Iron Cross twice in WWI, and once after being “wounded” by gas and the other for being a courier who succeeded where others had failed to deliver. Hitler’s own experience was enough for him, unfortunately that does not explain his final solution and the use of gas so does leave some questions, but in combat he was the reason the Germans did not use it.