Again, to be perfectly honest, I don't think it would help and it would be uncomfortable. The usual BCG schedule is one a week for six weeks, then a healing period. If a cystoscopy shows still no cancer BCG maintenance starts which is usually once a week for three weeks and this is done every two or three months for about 2 years. The patient has about a day of "discomfort" (urinary burning, urgency, some bleeding). The point of BCG is to "kick-up" the immune system particularly in the bladder lining to fight off the cancer and as the treatments go on and the immune system reacts the side effects increase and include more of what I described plus fatigue. BCG is a long-term process and would not help your father's current pain issue while causing more discomfort.
So sorry you are going through this. We do it with our parents and our children will be there for us.
Sara Anne