Someone here recently reported that edge coat came off in warm/hot water.
Coach Rehab and Rescue Club
I don't know if Dettol kills mold or pollen spores, although it kills bacteria and most viruses.
I would first wipe your bag down with a cloth dampened with white vinegar, inside and out.
Then, as long as the bag is thoroughly dry, I don't see why you couldn't put it in the freezer in a sealed bag. If it works for you on your books, it should work on the bag. Mold and pollen spores would be deactivated. Mold spores could re-activate if temperature and humidity became favorable for them.