See Create Deformers > Jiggle Deformer and Advanced deformer options.
You can only paint weights on one jiggle deformer at a time. If you select more than one jiggle deformer, you can only paint weights on the active one (the one that provides color feedback).
If the surface has only one jiggle deformer, you can select the surface alone.
To create disk cache for jiggle deformers
Maya creates the jiggle cache and creates a permanent jiggle cache file for each jiggle deformer in the scene. The file or files are in the current project’s data folder, and are named scene_jigglen.mcj.