I think I might try increasing the brine refill to the max for a while, to see if that either washes out the salt bridge, or at least removes a lot of the salt making the hammer and chisel able to break through later.
I cleaned out my impacted salt mass in my separate brine tank several months ago. I am glad I was not paying myself by the hour. Salt is heavy. I am thinking I had 200 pounds of salt in there. I wish I had thought of trying raising the brine level to max. I did not have a salt bridge as it turns out. I feel the salt was there for many many years. The salt was fairly dirty, so maybe I was better off removing that salt. Having a separate brine tank helped. I did not have a salt grid or anything besides a plain tube; the old Autotrol has its air check as part of the controller.
I now add less salt, and keep the water level partially visible.