What is "dull as dishwater"

Usage examples of "dull as dishwater".

For the sake of my sanity, I hope the rest of our lives are as dull as dishwater.

Laughing with John lessened some of the ache for the sound of Papa's voice, but she was sick unto death of being forced to eat every ghastly, greasy, tasteless meal with the seven other passengers, all strangers and all as dull as dishwater.

He had most of his material now thanks to his interviews with Kramer, but I couldn't tell him those interviews were worthless and that Kramer was only playing the role of a Croesus while the true millionaires, especially the ones from Texas, were dull as dishwater.

The Synthesis group, which had proposed it, was obviously sincere in its desire to unite all the radical elements but, as Hamp whispered to Max Finklestein, sincerity alone was dull as dishwater.

But they seem as dull as dishwater, and completely out of place, in a live action world.