I'm so sorry to hear that you are going through this with Rudy
It's good that he's a bit more comfortable today - it is a very hard balancing act with the medication, you need to keep adjusting the doses until you find what works for him.
I don't know that I'd want to put one of my dogs through that procedure for just a few days relief, financial considerations aside - I'm not sure that a vet will carry it out that frequently anyway. I think maybe you should be asking the vet at looking at a different diuretic? Could you get to a cardiologist?
I hope that Rudy keeps as well as possible for as long as possible