The commode would have typically held a chamber pot although this one may have been used differently in later years !!
Cleaning a painting is not difficult,, dirt and dust wears on the surface and does more damage than anything !! First take it out of the frame !! Then just take a pint of distilled water and add a teaspoon of Dawn dish soap !! Plain kind, not one with additives like bleach or fragrances, then dust the surface off with soft brush and use a soft cloth, damp only not soaking wet, and the water & soap to get the remaining dirt off !! Can use an artists brush if paint is thick like an impasto to get dirt out of creases !! When all dirt and grime is gone, place a fan in front and let dry a couple of hours !! Then reframe !! Once paint, no matter if oil or acrylic is dry, ( and this can take from 3 or 4 months to a year) it is very stable !! What can be damaged is the canvas most often and that can ruin the painting !!
