Yes you can it is your body!
However I would advise that you allow your Dr. to administer the BCG treatments.
I have had 3 bladder scrapings aprox a month apart along with BCG treatments.
I have been cancer free for 2 years just found out it is back now in my Urethra just outside my bladder, next month having bladder, prostrate, and part of my urethra and lymph nodes removed and having an Ileio conduit with an ostomy with external urine collection bag.
Just my 2 cents morth.
All the best to you.
Blessings,
Tim