Yes, it is perfectly fine to wash dishes after writing for many hours. Washing dishes can be a good way to take a break and give your mind a rest from the mental exertion of writing. It allows you to engage in a different physical task, which can be refreshing and help prevent fatigue or mental burnout.
Taking short breaks during long writing sessions is essential for maintaining focus, productivity, and overall well-being. Washing dishes or engaging in any other light physical activity can be an excellent way to stretch your muscles, clear your mind, and return to your writing tasks with a fresh perspective.
Remember to listen to your body and mind's signals, and if you feel the need for a break, don't hesitate to take one. It can be beneficial for your overall productivity and creativity in the long run.