Becca update - spit bubbles and "off" formula

Rebecca now blows spit bubbles and will sometimes drool. More interestingly, she is starting to be able to fall asleep regardless of whether she is being held or not (hooray!).
Furthermore, she has finally developed an interest in the rattles that hang from the beam above her vibro chair - in particular the plastic pig. Rebecca likes to watch the rattles swing, and seems to have figured out how to make the chair rock so that this occurs. This produces smiles and happy goo gaa noises.
We have had to switch brands of formula for Rebecca after an unpleasant experience with Similac. For economical and practical reasons, we purchase formula in large containers, in powder form. For some reason the last container of Similac we purchased was not right. It smelled "off" despite an expiry at the end of the year. Unfortunately, I noticed the smell of the formula only after having mixed it up and fed Rebecca several bottles. I have a very keen sense of smell, and finally went back to the container and confirmed that something was not right. Rebecca had also been behaving oddly - obviously hungry but repeatedly rejected the bottle and being overly fussy in general. I called the 1-800 number on the container and spoke to one an RN who confirmed that it is possible for the powder to go "off" if stored at too high or too low a temperature. I am supposed to purolator the bad container to them (at their expense). I have retained samples of the contents for myself because - well, I suppose I am not a trusting individual. At the end of the phone call (which incidentally took place in the wee hour of the morning), the nurse made a series of Similac sales pitches which I found particuarly distateful under the circumstances. I informed her that I was no longer interested in purchasing their product. I can't say how horrible I felt about feeding Rebecca bad food. I was simultaneously capital A angry - maybe I will look over the regs and see how these products are controlled. As a consequence of our experiences, we have switched to Nestle's Good Start formula which smells right and has caused no problems (and supposedly is easier for babies to digest). Once we switched - the old Rebecca was back (as Greg so aptly put it). The only remaining issue is that despite multiple washings and sessions of sterilizing, the bottles and nipples seem to retain some of the "off" smell. I don't know how I should proceed about that - there must have been some permeation of the plastic - from which (if I put my chemistry hat on) - I should be able to deduce something about the nature of the "off" component (or components I suppose). Unfortunately, I am unsure what I could use beyond soap that would not pose a risk to Rebecca. Vinegar - with many subsequent rinses??? We gave the lot number of the formula to employees at the pharmacy where we purchased the product, but I doubt they have done anything about it.