One great scholar Allama Muhammad Hussein Al Husseini At-Tehrani says that when we do an act of charity or a good deed for the dead, it should be with respect.

He relates a real life event as told to him by another great scholar of Islam Agha Buzurgh ATahraani who said that when he was small he lived with his family in Tehran. It was a few days after the death of his grandmother and he was with his mother in the kitchen while his mother was cooking some food.

A beggar knocked on the door and Agha Buzurg decided to give the beggar some food as an act of charity on behalf of his grandmother so that she would get a reward. Well, because he didn't find a suitable vessel in which he could put the food he quickly grabbed a cup which they used in the bathroom and put the food in it and gave it to the beggar.

That night his father dreamt a strange dream and woke up in the middle of the night and related to his mother that he had seen his mother and she was annoyed, because she had received some charity in a bath cup and her friends had all made jokes of this. She stressed that when you stand up to do an act of charity it should be done with respect.

Agha Buzurg says that his mother was taken back by this incident and on straining her memory she remembered that Agha Buzurg had given the beggar some food in a cup used in the bathroom. (MAAD SHENASI PAGE 188)