the germs are a virus...the dettol aerosols claim to eradicate cold and flu viruses but smell. once you have both had the cold, then your own bodies will make efficient protection given that you are both in good general health. Bacteria and viruses are airborn but don't stay in the air, they settle on surfaces with dust particles. If you want to make the bedroom more hygienic, do what they do in hospitals and clean thoroughly, damp dusting to keep the dust in the cloth/mop and not in the air. Change and hot as you can wash all the textiles in the bedroom. Clean the toilet and shower as though the clean police were going to visit and pay particular attention to areas that you both touch like door handles. Change towels regularly and don't share them. Use paper tissues once only, clean your hands afterwards and dispose of the used tissues regularly.
If there was a spray that would help, don't you think the NHS would be using it already?