So just use the peroxide in the spray bottle without adding water? Will have to try it.
A fine mist spray bottle if you have one on hand — or go to the Dollar Tree and buy one of those nasal decongestant spray bottles — and replace those contents with this most natural alternative.
Another variation of that use is just to dump out the essential oil diffusers, clean the residue and then put in 3% or diluted to 1:35 purified water, and run that all the time to eliminate odors — in addition to being antibacterial, antifungal, antiviral, etc. — enhancing the oxygen availability in your environment — just as they do for people on life support.
The dilution is preferable to the full strength spray only as needed — because prolonged higher concentrations may cause eye irritation and diarrhea — because it may begin to kill off your intestinal flora at prolonged high concentrations — just as the predictable side effect of any effective antibiotic, antifungal, antivral, etc.