hi! when i used to sterilize bottles using boiling water, i washed all the parts with warm, soapy water, rinsed them and put them in boiling water for 5-10 minutes and let them dry on a dish mat or paper towels.
I did it the same way as Shaada! And my pump parts/dummies/teethers if I ever needed them too! You're best to try and put the bottles together when they are still hot too, for better sterility :)
I soak/wash bottles in hot water, soap and occasionally bicarb soda. Rinse throughly under hot water and then boil them for 5-10mins. Done this across 3 babies and never had an issue
I’ve done it a few times genuinely just taking the bottle a part and giving it a good wash and fling it in boiling water for about 45 minutes. Then washing it again. But also are you maybe using to much Milton/not enough water as I’ve never had an issue with the smell. There’s always a slight smell but never to the point I can smell it over milk