I have read about this in the past, saw some videos but i let it go due some other matters that i had to take care. In the past i have used some other methods as foam inside the airways and a spray inside the cabin

https://www.sonax.com.au/cdn/shop/files/action.jpg?v=1652248204&width=720

with a/c on and the recycle air button in On position. Few years ago i went to a repair-shop to open the a/c from the front (engine bay) and give a thoroughly cleaning of the evaporator.

Few weeks ago i remember the Dettol it and i had the thought to give it a try.

I have found in my cabinet a spare (non used) extra-long plastic nozzle

which was for an a/c cleaning foam spray and surprisingly it fitted perfect in the Dettol can

so i use it as we usually do with the other a/c sprays.

https://www.moje-auto.pl/wp-content/uploads/2024/10/19-535_MOJE_AUTO_-_Nano_Preparat_do_Czyszczenia_Klimatyzacji_200ml_12_670f6ece974c6-650x434.jpg

I laso found anothe plastic nozzle from WD-40 type sprays, remove the dettol's one and fit it.

Worked perfect, no leaks and i spay some inside the air vents.

like this:

https://shop.errecom.com/wp-content/uploads/2019/07/AB1084_Evaporator_Cleaner_ambientata_1500x1500_AUTO.jpg

https://pbs.twimg.com/media/EHci4glWoAE5MHo.jpg

Next is inside air air cabin filter case.

Here it is:

As i have seen here:

https://i.ytimg.com/vi/myktSWWjp88/hq720.jpg

which i find it better than this way:

https://autoservice-lepidas.gr/wp-content/uploads/2023/07/acdisinf-775x517.jpg