What species of Baobab? When I germinated the Australian Baobab, Adansonia gregorii, I scratched the surface of the seed on one side with some fine sandpaper, then threw them into a mug of boiling water straight from the kettle. I left them there overnight then planted them the next day. I think I got about 80% germination from memory. I believe most Baobabs are similar.
Cheers,
Dave.