For cleaning - you definitely want to sanitize everything with bleach once after the treatment is done. For now, I would take out everything that is normal stuff and bleach it, as I mentioned. You want to use a 3% solution of bleach in water. Then you want to rinse it until the bleach smell is gone. Finally, you want to bake everything in the oven at about 300F for 30-45 minutes. That should kill anything. The wooden log will be fine after that treatment.
As for probiotics, you can use soy yogurt. I have also used AcidophiLiz+, which I ordered from beardeddragon.co. I think it was about $7. Either one should be just fine.