Silver Nitrate Flush to Treat Complicated UTI

I am a 52 year old woman with a history of recurring kidney/bladder infections. I underwent a cystoscopy which was performed by a urologist. His diagnosis was ''extensive changes of squamous metaplasia and cystitis cystica throughout the bladder with an amazingly normal bladder capacity of 600 cc suggesting an extremely high pain tolerance''.

I was then treated with zithromax and flagystatin for a period of 2 weeks and a second antibiotic was added after one week of taking zithromax. The urologist strongly recommended silver nitrate intravesical therapy in the event of unsuccessful treatment with the antibiotics. The antibiotic treatment was not successful, therefore the next step is the silver nitrate flush. I am extremely worried about the silver nitrate flush as I have never heard of it.  My question is - Is silver nitrate the best course of action????

I posted my question on two forums.  

Lucie