A wrist roller, by all means. Stand on a box, bench, etc for extra height and use a longer rope. Like doing higher reps...if you can handle the burn.
Reverse BB curls, with a false grip. Very overlooked exercise for better forearms and a stronger grip. Elbows never leaving the sides of the body.
Chins from a overhead beam, using only finger tip gripping. Also one arm finger tip holds (static). Some rock climbers I know have very impressive forearms and gripping strength, women included, do this as an exercise (weight added). Can try a pinch grip when becoming advanced enough, which will improve the thumb strength also. Usually start with static holds.
Taking a heavy weight off a PR (or whatever) and just holding it in place, false grip while standing. Don't let the bar touch the legs at all. If Dl'ing 400lbs from the floor, than try in the 450 to 500 lb range for these static holds. Can advance quite rapidly, as most lifters do. Also try these with DB's. Can cut a piece of heavier rubber hose to length, split it down the middle and place it over a BB/DB for a thicker gripping handle. Also works on a chinning bar.
Art Jones was greatly in favor of from the finger tip wrist rolls (with BB) and curling up the grip at the top position. Gironda, not sure. Good Luck.