Don't get it wet? Why? People boil horn to shape it. Same collagen base. What's the difference?
I am not a scientist so 'why,' would be an opinion. I do know horn and ivory is not in fact the same material. You could do your own experiments and get it wet, then wonder why it cracked and warped. Or simply believe me.
I think fossil ivory could be boiled and shaped! "If" if one did this for a reason. Evenly wet evenly hot bend slow dry, as in 6 months. It's possible I think. I have taken wet ivory right out of the ground and bend it to flatten pieces between boards and clamps in order to get flat knife scale sets. (keep clamped a month) So possibly dry ivory could be wet again. One issue is, I find it, for free. if it goes bonkers I say 'Whoops that didn't work!" Most people bought it and would get to say "There just went $500 out the window!" is that ok? The easier answer is try not to get it wet if you do not know what you are doing. For example do not use a wet sander to keep dust down when sanding ivory. There is a reason those in the know want ivory out of the ground a year and ask if it is dry. Keep in mind I speak from 40 years experiences and thousands of pounds of ivory.
Yes I have bent horn. Horn has hair -like structure and is related more to our fingernail, when an ivory product has no structural strength in the same way. Horn can also crack if dried incorrectly. I think as well, when boiling horn, something is removed and will never come back. The dry horn is not the same exact product anymore. I think what leaves is a gelatin as is in skin. The gelatin helps hold the hairs together so remove some, get the rest soft and the fibers bend.
Ivory is simply different. No hairs no gelatin. I used to boil walrus ivory ivory and it is not the same after drying, something is gone. it is more brittle ,looks a tad different. Just getting it wet did not help with bending. Feel free to comment or ask a related question I have dealt with a variety of products over the years and am glad to help or even learn if anyone knows more than I do, had a different experience.