Just buy round toothpicks.
Then lay a piece of sandpaper on the counter, lay a toothpick on the sandpaper and give it a few swipes until you've got a bit of a flat side on the pick. Then flip the toothpick over and do the same to the other side. If you don't have any sandpaper you can do the same thing with the toothpick on your back patio or driveway or some other concrete surface.
Once you've flattened the picks and before you put wood glue on them cut them to length by standing one up in the hole and marking the pick to match the hole depth then removing it and cutting it off at that point, then cut all the others to match. Do the same thing for the picks that will go in the other hole.
Remember, when you pound the stud inserts back in the bass body to use a block of wood on top of the insert, don't hit the inserts directly with a hammer or you'll ding them up. Also, when starting the insert in the hole, tap lightly at first and make sure the insert is going in straight and not some goofy angle.
If for some reason you get any wood glue on the body just wipe if off with a moist cloth or paper towel followed by a dry paper towel. if you let the glue dry on the finish it will be harder to get off.