AAARGH !
I made this mistake once ..... i was working with a friend, at his home, on one of his mech-electric projects, and at the end, took a bottle of that what was looking as "hand soap" for wash off my hands ..... oh, it was cleaning very good, immediately the grease and all the rest was going away ..... only, after 4 or 5 seconds, it started to burn
..... i washed quickly my hands with water, and continued for 5 or 6 minutes, before it stop to burn, and for all the time i was feeling my hands burning and "feeling soaped" ..... that damn thing was concentrated caustic soda for clean industrial machines (to be used diluited 30/1
), that he had stored in a hand soap bottle, and the "soapy" feeling was the external layers of my skin, slowly melting
I was lucky, i reached to clean it all away before to have any permanent damage, but when it stopped to burn, i looked my hands, and had no more fingerprints, and the skin remained very sensitive for more than a week ..... i had washed off all the external layers of the skin
I personally don't suggest to use caustic soda .....