Other uses of Onion Juice apart from cooking;
1. Onion Juice + Honey = Instant cough relief
2. Applying Onion juice on bald head helps regrowing hair. It is every effective.
Another great use is for ear infections. During summer months after a lake session or two, if one of our kids gets a sore ear we make a compress of onion bits (usually quite juiced up) and place it over the affected ear. Quite often - within minutes many times - this just solves the ear-ache and the kids go back to the lake.
[1] https://www.livestrong.com/article/287051-how-to-use-onion-a...
[2] https://www.quora.com/Has-anyone-had-any-success-using-onion...