We used regular Dawn, just a smidge. We would boil them every couple of weeks or so to just sterilize them. I loved the playtex bottles. The kids took those best and they were so easy to deal with.
I only boiled them before first use. Between uses, I just ran them thru the dishwasher. Every week or so i put them in my microwave sterilizer. They don't need to be boiled every time.
I hand washed them with hot soapy water. I never had enough nipples to last until I was ready to run the dish washer. I boiled them after each time DD was sick.
I used Playtex drop-ins for both of my kids, and Yes I steam sterilized the nipples after each use. I washed the nipples and bottle parts with regular dish soap then steamed the nipples in the microwave. I also sterilized my pump parts after every use.
We just use hot soapy water too - I use them too often to put in the dishwater on a regular basis. I have boiled them a couple of times with other things, but not on a regular basis.
Re: Playtex bottle users..
this
Ditto this...I felt like the steam in my dishwasher was hot enough.