Evening John,
Years ago my younger brother got bitten on the butt by a Red Back spider,
very similar to the US Black Widow, and for young'uns, deadly, Well on
went the onion, and within and hour, almost no evidence of the bite,
swelling was reduced to a small localised area, and no toxicity effects..
Fantastic!
It appears that you guys are the world spider experts.
So, this will work even on bites that are several days old and advanced.
My bite is 8 days old. I always have a good supply of onions around.
Wayne