As noted, the joints have to be cleaned of the old glue. Replace any
dowels with larger dowels, where applicable.
I use the gauze bandage technique occassionally, as well as paper
towels for that type of filling. Instead of wrapping it around the
dowel, cut the gauze or paper towel into a cross, like the American
Red Cross' symbol, and it stuffs into the dowel hole similar to
loading a cloth wad into a muzzle loader. It folds itself into the
hole. This allows for dry fitting, too, if you need multiple crosses.
In cases where you think the stuffing may be too much and splitting of
the wood is suspect: prior to assembly, tighten a screw clamp (hose
clamp) around the suspect piece, then assemble. On a square member,
where a screw clamp won't make complete contact on all surfaces,
insert wedges into the spaces for more even compression all around.
Additionally, to assure your repair doesn't fail, never remove the
clamps. Is it April 1st, yet?