Is it sufficient to change the cloth once a day, or must it be changed with a clean one at every ablution due to the hardship involved?

If the drops cease for a time sufficient to perform prayer with a valid purification, then one must wait for them to stop, then perform istinja’ (cleaning oneself after relieving oneself), wudu’ (ablution), and remove the bandage before praying. However, if they do not stop, then your ruling is that of one afflicted with incontinence: you place the bandage and perform wudu’ for each prayer after its time has begun. There is no need to re-bandage the area.