i used to work at an art store and once a lady busted a bottle of etch on her leg.
she went to the washroom to clean it off but soon after it started burning and the ambulance was called
my boss said that if a mass quanity is spilled on you and you try washing if off, the water activates some chemicals and makes it worse.
how much of this is true i do not know
anything that can eat glass can't be good for your skin anyway
wear some rubber gloves