A method for refurbishing a tap-hole including making a channel trough a tap-hole block, restoring the channel to form a refurbished tap-hole, detachably connecting a prefabricated refractory insert including a shell to a clay gun, where the insert includes a first and second ends in axial direction, where the second end is blocked, an opening arranged on the first end, a hollow passage in the axial direction, where the hollow passage is accessible through the opening, a plurality of lateral through holes, aligned in a longitudinal direction of the shell, with a constant interval covering 10-25% of the shell, the method further including inserting the insert into the channel, where the clay gun is fluidly coupled with the insert and the channel, injecting a grouting material from the clay gun into the insert and through the through hole into the channel and, disconnecting the insert from the clay gun.