Sorry, the inverted, center-weighted, cloth filter is not replaceable with a closed filter bag. You have to change the entire unit to one of these alternative units: https://builtinvacuum.com/help/beam/units.html
. These units use the same pipe and wire and work with your system and tools. Meanwhile, the best way to clean your unit is by using trash bags to keep down the dirt. Dump the bin into a large trash bag while it is completely inside it. And use a bag around the bottom to shake out the cloth filter.