Implement a reset button per facet
Have you tried the following?


Navigate to the facet setting page (/admin/config/search/facets/facet_name/edit)
under widget set it to List of Checkboxes or List of Links (not sure what you are using)
Within List of Checkboxes setting or List of Links Setting, there should be an option Show Reset Link. 
Enabled it and it will show a Reset Text input box where you can add Reset Facet or whatever you need.
Apply other settings and click save.