I made one of these years ago with household stuff. a tall generic rogaine bottle cap and a latex sleeve cut from a finger of a dish glove. Packing tape makes very, very strong hanger (in shear). You do have to keep buying gloves, they eventually tear. I’ll probably do it again with a cut up pill bottle. Another bonus, no moving parts, totally non metallic. you do have to burp air out to create the start of vacuum, the stretch creates the rest.