Eventually

Turns out bucket and sponge was the correct answer. Also a scrub brush.

You sit in the bathroom, staring down at the bucket full of filthy water. You address the water, unsure whether whatever remains of your mother can still hear you...or anything at all.

"So I think that we've gone as far with this as we can. The question is, where would you prefer that it all end?"

"Sink?"

"Tub?"

"Toilet?"

"Let me know soon. Sorry, I can't hear you. If you don't make a choice soon, I'm going to be **** to do it for you." Then, with no pause: "Okay then, tub it is!"

You hoist the bucket and fling the water bearing the destroyed particles of your mother into the tub. It sloshes around, seeking an exit via the drain...

...which you have taken care to block.

The water settles and becomes still. "Sorry Mom, but I had to see if this would work. If it doesn't, I'll go ahead and pull the plug." You raise the calculator and push the Cancel button.

Your wet, naked mother appears, lying in the tub, breathing heavily. You can't tell whether the look on her face means she wants to **** you or fuck you.

Then she has a massive, howling orgasm.

You approach, and drop a data key - containing the video of her final sidewalk obliteration - between her breasts. She stares up at you.

"You're welcome," you say, grinning. "Now if you'll excuse me, I'm sending myself to my room. It seems I've been a very bad boy."

And you leave the room.