On the kitchen Sponge...

I would take a massive dumb in the middle of their living room, and start taking bits and pieces of it and rub it in very inconspicuous places. Like underneath door handles and such. Then, the smell will fuck with them and they wouldn't know where the smell is coming from. Shitting like a ghost and stuff.

I rub it on the inside of all the air ducts

In the back of the toilet