I had something similar happen when a woman beside me pulled out wet wipes and began maniacally wiping down everything around her including the opposite arm rest, inflight magazine, safety card, tray table, IFE screen. She then politely asked me to lift my arm to wipe to down the shared armrest to which I agreed. I drew the line when she wanted to wipe MY tray and screen too.
The remark to the OP by the woman's husband suggests this is pattern behavior and not a response to coronavirus. Anyone who would scrub down a seat going from Newark to Fort Lauderdale due to a virus in China should fall into the category of mentally unbalanced.