Fill an empty spray bottle with water and get a rag. First show your child how you spray once then dry it all up before spraying again. Next help your child do it once or twice. If they refuse to dry after spraying you can put the spray bottle in time out for a bit. One variation of this is to just let them go outside and spray all the plants to “water” them. Spray bottles are AWESOME for building hand strength which is vital for fine motor skill development.
Our house has glass railing (instead of traditional spindles along the stair case). It drives me crazy because it is constantly covered in fingerprints. Last year I decided Mr Rockstar was old enough to learn to clean them as a chore. It turns out he LOVES cleaning windows plus his sisters do to. They will beg to wash windows. This week the kids washed the back door a few hundred times just for fun. It is a great activity to build fine motor and concentration on completing a task.