I have never got much out of washing/drying poly gear. It does tighten up (smells better too). But after a rep or two, it seeems like it’s back to where it was before you washed it. The Powerwash soap that Titan or Inzer sells didn’t really impress me either. Your results may vary- that’s just what my experience has been.
You can get the straps taken in. If you are a conventional puller, tight straps and moderately snug hips is the way to go. This is not a complicated alteration to communicate to a seemstress or dry cleaners that doesn’t understand our gear adn may not speak very good English. They should put heavy stitching in the new seam, but dense stitching and special thread isn’t nearly as important for this as it is for shit like taking in a bench shirt or the legs on a squat suit. Actually, I’ve done this myself by hand before. It took about $2 worth of supplies and maybe 45 minutes. Buy a thimble big enough for your pointer finger (I learned that one the hard way).
Of course, if you’re not accustomed to pulling in a tight suit, you may have a learning curve if the straps are taken in a lot. That’s something to consider in terms of timing of when you get the suit taken in versus when you have the meet.