Am I cleaning her bottles correctly?

I use plastic bottle. And I get the sink water as hot as it’ll go. It gets really hot, I can’t have my hands under the water for more than a second thats how hot it gets. I use foaming bottle soap by babyganics. Get the bottle wet, Pump the soap in the bottle, shake it around and run it under the hot water. My SIL said i NEED a bottle sterilizer. How do you guys do it?