You could just go for a harder wood. Perhaps oak or ebony? Pencil wood is particularly soft and splintery because you have to be able to sharpen them. Are the different colours important? Ds likes things red orange yellow green etc to match the rainbow. He finds circular handled toothbrushes good for his hand which hurt if not holding.
DS2 (ASD, Hypotonia, hypermobility, LDs) chews. Specifically he has a pencil obsession, in which he has to have pencils slotted between each finger (usually two per gap) in his left hand at all times when he is home. He puts them down to eat dinner and to go to the loo, otherwise they are always in position. He has to have them lined up just so, when he does put them down. This week he chewed his brand new pencils down to splintered stumps (from both ends) He always chews them but he has started SN college (he is 16) and is stressed and he has chomped through them even more quickly than usual. His computer is covered in splinters of wood and heaven knows how much he has swallowed!
At 16 I accept his lining up and pencil hand is part of him. BUT his anxiety means his chomping is getting worse and it can't be good for him!
I need alternatives that slot in his fingers like pencils, provide oral feedback and won't splinter! ( And I'm trying to deal with the anxiety that his crappy college are increasing!)