"Googling" didn't produce much. I have a Hesco catalog that would cover the parts for that machine. With the exact model in question would be easier to see if if they are still available from several suppliers.
Before reading this, I did check with Vac+ only to find the last 4 packages were either just bought or they got tossed during the big cleaning when one of the stores closed.
I know what the packages looked like so if they show up on Ebay, I will know where they went. They were Dusto brand.