Ratcheting mechanism for cloth bracelets so they can only be pulled one way:

I think a 2D revolve profile is sufficient.

(X,Y,Z)

Draw a vert at (4,0,0) then (3,0,5) then (4,0,5). This triangle can be repeated upwards to the desired height. The outer wall can be set to a minimum thickness. Then use a screw modifier without applying.

The right triangle profiles should let cloth pass through and block it on the way back.