What were you using to make your smoothies? I haven't experienced this problem with mine needing plunging for smoothies I've made so far (nor have I never seen a barista use a blender with a plunger).
TBH, I wouldn't mind a good recipe for a thicker smoothie
Frankly, I don't remember. It's probably been a year since we had it. As far as recipes, I don't use any. We always have a variety of fruit (frozen and fresh), juices and veggies around. Whatever is starting to look old either gets tossed into the blender or frozen and used later. As long as it's sweet enough, isn't too stinky (broccoli) and doesn't come out brown, it seems to go over well.