Congrats on the successful tube feeding; glad to see that went well
I have a few suggestions on your setup, though you may just want to wait until treatment has stopped to change things too drastically. I would go with a substrate such as newspaper or blank paper towels, just so that you can be sure your snake doesn't have mites or ticks. I had one snake who seemed mite-free, then in a few months.. mites. These substrates will give the potential buggers no place to hide, so you acn't miss them. Also, sand can possibly get caught in the snake's heat pits in the face which is not a good thing; and I would dare to say it may contribute to his dehydration, as it is a drying agent.
I am glad you're here to get knowledge Wecome to the forum, by the way; this is the most helpful place (in my humble opinion) on the Net.