You can wedge the crack open far enough and slice the wood out from inside the break. That will remove both the old glue and any other repair attempts that may have been made.
Plus make plenty of room down inside for the crack so to be clamped back together again and have some success of the outer surfaces joining back together at the surface and hiding the crack. That's where it counts after all.
You'll still need to doctor the repair to hide it completely. But it will be strong with proper adhesives and clean wood to work with.
Another way is to clamp the existing joint as it is together if it will join up OK with the old glue still in it. Clamp it together till the crack is almost together,,just about touching,, but not quite.
Then you use a coping saw or even a jewelers saw with a blade that you have stoned most all of the 'set' from the blade. Use a coarse cut blade as it will need that to get thru the old glue and wood.
Carefully cut thru the crack following the line of the crack both top and bottom with the saw blade.
This will remove the old glue and displaced wood and make a clean cut right thru the crack.
When complete, the narrow cut can then be unclamped, opened slightly with wedges and glue applied and then clamped back up tightly.
If done right the saw kerf cut will be the new crack line and should blend in quite evenly with the natural grain of the wood flowing right thru it.
Some doctoring of the finish is usually still needed but it's not like there are filler pieces and inlayed pieces to try and hide.
Any small dimension changes in a bbl or part inlet can be adjusted as needed.
Saves using nasty solvents and the glue up afterwards generally doesn't end up lining up too well with lots of small pieces being filled in and then trying to hide them with finish.
Just another way to do something. Not always the one and only way.