I occasionally nebulize a 1.5% hydrogen peroxide solution. 50/50 3% with diy Himalayan salt saline. I do this as a mostly but not always former heavy smoker.

Or maybe its a 1%, I don't remember but I'd played around with a couple different ratios.

I find it helps break/loosen phlegm up for coughing out.

I wouldn't recommend this whatsoever if you have good healthy lungs. Not that it burned or caused any discomfort, its well above the strength I've seen of any hydrogen peroxide nebulizer solution I've seen.

I occasionally nebulize a 1.5% hydrogen peroxide solution. 50/50 3% with diy Himalayan salt saline. I do this as a mostly but not always former heavy smoker.

Or maybe its a 1%, I don't remember but I'd played around with a couple different ratios.

I find it helps break/loosen phlegm up for coughing out.