Its doable. Not ideal, but if his teeth are bad then it may be the only solution you really have.
They can survive being toothless and can live fine. So two examples for you: I had one girl who had premature tooth wear. While not toothless, she didn't have much teeth left. We switched to soft foods and she did fine on that for 2 years.
Another started out spitting out teeth. He had developed a tumor (removed and recovered), and yet later his teeth started getting loose and infected. Eventually he was just toothless. He was fine for over a year living on moistened kibble.
I shouldn't say the biggest trouble is gettign them to eat, but it can be in the beginning. The biggest hassle sometimes is getting their GI to deal with the extra moisture and finding foods they can eat and planning out their meal plans.
The excess moisture in the beginning typically triggered very loose stools in my little ones. It was messy in the beginning, but their systems seemed to adjust. However, looser than usual stools would happen from time to time.
You also have to be very careful what you give them. Canned foods that have chunks or shredded can become problematic for them. And insects pretty much are no longer an option since they cannot chew them up.
I've had a couple who just had bad tooth wear. Mealworms quickly become a non-option. And eventually even soft bodied insects like waxworms were a no go too. They become choking hazards, or they simply cannot chew them up and the insect passes through their GI whole (its not fun finding a large white blob in a hedgehog stool).