I don't have "protocols".... I do not like that word for training solutions, It sounds pompous.
I simply add bonus grip work about 3x a week, working on different types of grip strength:
Rack 1/8th deadlift hold (basically hold the barbell in the finished deadlift position, strting the bar 2-3" below the end point).... I gradually work up to the heaviest weight that can be held for 9 seconds WITH A FAT BAR then continue ramping with a regular bar.
Pinch grip deadlift hold (using a plate loaded only on one side of the barbell and pinch grip deadlifting it)... working up to the heaviest weight that can be held for 15 seconds, then going down in weight by about 20% and doing 3 sets for max time
Pull-up hang 3 sets for max time
Captain of Crush gripper work... a combination of various iso holds (with more resistance than you can close, get in position with two hands, hold with one) and repetitions with an easier gripper for 5-10 reps per set
Then there are other things you can add to your regular training...
GOERNER DEADLIFT RAMP
Deadlift with only 1 finger per hand, ramp to max for 2-3 reps
Deadlift with 2 fingers per hand, continue ramp to max for 2-3 reps
Deadlift with 3 or 4 fingers per hang, continue to ramp to max for 2-3 reps
Deadlift with regular full grip, continue to ramp to max for 2-3 reps
Deadlift with hook grip, continue to ramp to max for 2-3 reps
ROMANIAN SNATCH GRIP DEADLIFT
Sets of 6-8 reps, not touching the floor, slow eccentric
And doing farmer's walk
And obviously doing the Olympic lifts from the hang without straps is also very effective at improving the grip