If he gets home healthcare once a week that is for the nurse. Along with that you can get a "helper" to come over, tidy up the living area, change the sheets, help with a bath, etc.
I hope you and your brother are on the same page in all this. About the only thing worse than what you are going through would be adding more stress to an already stressful situation. And, of course, if you feel your father is being left alone too much for his personal safety, you have an obligation to become involved.