Sylvester had done it before to his spy enemies. Dissolving a body with low pH value acids such as hydrochloric acid was the easiest and the cleanest way to get rid of a body.
But, if the acid is not strong enough, it could lead to anything but death.
So, the fact that the woman was sitting in the acid silently meant that she had already screamed all she could. She had cried all she could and had already suffered through all the pain she could. Now, her flesh had been melted off, and the pain receptors were damaged. Or perhaps she was in such a shock that the pain wasn't even registering in her mind.
"You inhuman pests! Why do such to a completely innocent person?"
Sylvester quickly punched a few holes in the bottom of the metal container to let the acid flush out. Then, he used water manipulation to pour a soft stream of water all over her body in order to remove any remaining acid that may still be on her.
