RI treatment

[Bluebonnet Herp]

So more then 7 weeks have gone since i´ve first recognized signs of an RI or better i thought so. He is eating like a champ, is providing me 100% complete sheddings. Inside his tube i can hear nothing, when he breaths. He shows absolutely no signs of an RI - neither by lifting up his head or breathing with open mouth, no saliva, no mucus, no bubbles. He is absolutely calm and stays in his hide with just laying his head and a portion of his neck outside on the ground. When i take him out, i first pet his back with the hook, then take him out slowly, supporting the first and last third of his body. He increases his breathing, hisses when I try to lay me ear on his body for trying to hear suspicious noises. And still since day one he has this crackling, smacking sound when he breaths. It is like "crackling - like a plastic bag" - nothing - nothing - crackling - nothing - nothing and soon. I was wondering if that maybe could just be because of his increased heavier breathing - maybe I just hear his glottis then and he is perfectly healthy.
I also have been twice at the vet and he said, that his mouth , his glottis and his throat are perfectly clean, with a nice colour and no mucus. A x-ray of his lungs was perfectly fine too. We also made two swaps - one of his throat and one of his glottis and the results just showed normal "standard" bacteria, included also pneumonia bacteria, that could get optional pathogenic - but haven´t. I also treated him with F10 nebulization weeks before but stopped after the 5 th treatment, because he did not react well on F10. I used the right dosage - 4ml of F10SC on a litre of water. He was stiffing up and gapping his mouth, wheezing and really had difficulty to breath. After a few hours he was back to normal. This bad reactions started at the 4th treatment. After the 5th was the same, I stopped it. He got 6 dosages of 0,2 ml marbocyl orally - one every 48 hours "Preventive - Just for the case of it", because on the swap samples the bacteria reacted well on this antibiotics. It did not alter anything. so I tend to think , what I've written above- that he is fine and I just misinterpret the crackling or smacking sound - maybe really just breathing noises - from his glottis........

What do you think, what should I do??

I guess just keep monitoring him since he seems to be making improvements.

I just got through treating an RI in a blood myself. I'd have to find the receipt from the vet to get the name of the medication, but the vet ended up giving her three shots of antibiotics over the course of a week. Not sure how, but it was one of those RIs that suddenly comes up out of nowhere and it was quite bad - discharge from the mouth, major bubbles from the nose, open mouth breathing, and gurgly sounding breathing. For the past two days, she seems to be clear though. No discharge, normal hissing sound when harassed.

Anyway, if it seems to pop up again, I would go the route of seeking injected antibiotics.