Yeah ditto likes to spend other peoples' money, based on his own income.
I tried a shop vac way back when but then quit with all the lugging one around and simply leaned the tank over a floor drain or 5 gal bucket and poured the water down some and then picked up the tank and dumped it in 5 gal buckets lined with a salt bag. Then I'd take the buckets outside and lift them out of the bucket and poke holes/cut short slits in them across the bottom and up the sides a few inches and stand them up to drain the water out. To separate resin and gravel I didn't use the salt bag, just the bucket and when outside somewhere where resin could dry and blow away harmlessly, I'd push a garden hose into the bottom of the bucket and float the resin up and out of the bucket leaving the gravel in the bucket to be able to pour it back in the resin tank before or after adding new resin. I always had the control valve in backwash when I turned on the water and during backwash the gravel went to the bottom of the tank. That got rid of all air in the tank too. Then put it in Rinse and compact the bed and I was done.
That flexible tube extractor is something I wish he had when I was replacing resin etc.. Any of his extractors will remove any mineral.