The hard part is selecting the clumps. As for assigning it to a bone in the rig it's pretty easy. You create a vertex group on the emitter object(mesh). Properties editor->mesh data->Vertex group->click plus. Then name the vertex group by double clicking and typing the name. Remember it is case sensitive. If you already have the rig created and the bones named you can select object, shift+select armature, and press ctrl+p->With empty groups. This will create all the vertex groups with names of the bones. Then use a Store Name Attribute node. Set to Float and point/vertex(Depending on Blender version). Set the name to the bone/vertex group you want to use to control it. Then set value to 1. Then the part I'm not sure how you would do it and that is the selection part.
OH, I just thought of something. You can Try going old school and use envelops instead of vertex groups. I use this with curve objects since they don't have vertex groups. You switch the armature bone display(Under viewport display of the armature tab in properties editor) to envelope so you can see the envelope's influence area. Then in edit mode you can use the envelope tool(Second option under bone size on the toolbar) or using Shift+alt+ctrl+s. Note: Size of the bones also affects the envelope and you can adjust the size of the head/tail/body by selecting them individually and using alt+s. You can also do this thru the n-panel with head/tail radius and envelope settings. To get the envelopes to work. Select object, shift+select armature, and press ctrl+p->With envelopes. Blender sometimes does this, but most of the time it doesn't so go to the modifiers tab and on the armature modifier uncheck vertex group and check bone envelopes.