Bottle and Nipples with Lingering Soapy Scent

Smart girl, avoiding a smell like that. Unfortunate for you, though.

I'd skip the soap and use baking soda in hot water, which is a good cleaner for all sorts of applications, cuts through fats, and is inhospitable to germs. It should rinse out with no lingering smell, and may even remove the smell from the bottles you've washed in detergent.

You could also try soaking the smelly items in hot water with a generous addition of vinegar. This can neutralize some kinds of odors. But many plastics are famous for absorbing chemicals, smells and colors, so they may be a loss.

There is a pure and clear type of handwashing dish soap on the market that does not leave any residue. It is recommended for breast feeding pump parts, but I am sure that it would work great in this situation as well. Look for it among all the other soaps. It is a clear soap, palmolive is the brand I think??

Try a tablespoon of bleach in a full sink of hot water. Let them soak for a few mins and then rinse really well. That's always worked well for me :)

How are you rinsing them? I would make sure the rinse water was fresh so that previously rinsed soapy items hadn't put suds in the rinse water. Also push water through the nipples to make sure they are thoroughly rinsed. Maybe try a differnet brand of dish soap. The cheaper ones might not clean greasy things well, but for bottles might have enough strength without leaving a residue.

I would try using a scent-free detergent. I've hand-washed the baby bottles and nipples using the Totally Toddler brand detergent, following the directions on the bottle and never had any smell issues. I washed in hot water and rinsed with plenty of warm water.
Now my toddler is older and uses a variety of kitchen utensils, I wash everything with Palmolive pure and clear (no dyes, no scents).

Try sanitizing them in the microwave. Medela sells sanitizing bags that are really easy to use. Put the bottles and nipples in the bag, add a couple ounces of water, microwave for just a couple of minutes. Each bag can be used 20 times.