Two of my most favorite toys are made by NobEssence and I am about to order my third. Just how wonderful do I think they are? Well, they edged out other toys that were high on my wish list, such as a JimmyJane Form 6, a Zini Roae, and a FunFactory Sinnflut vibrator. And, as much as I really wanted to finally order a Liberator position aid, my desire for another NobEssence toy was even stronger.
Wooden toys are absolutely phenomenal. And, no, splinters are not even a passing concern, given how absolutely smooth they are. (At least that is true with NobEssence toys -- the only wooden toys I've tried thus far -- though I've also heard wonderful things also about the company called Hardwood Dildos).
The only way I could see a wooden toy splintering would be if I decided to smash it with something, like a metal meat tenderizer or some other object, with the purpose of destroying it. And, after deliberately attempting to smash it and destroy it, it would not be functional anyway.