This is an update of an old post I put together awhile ago, this mix is still a pretty good one, worth repeating every now and then...
This is a mix I have used to keep coral snakes alive for many months without feeding them any natural food items at all. This can be used for hard to maintain, acclimate or start snakes. It can also help correct some problems by replenishing the digestive trac with probiotic beneficial bacteria. Snakes maintained on this mix shed normally, grow and seem to thrive. All signs of a decent mix.
I use Gerber meat baby foods, alternating between Veal, Turkey and Lamb. I use to mix all three together, but my results improved by alternating them.
To one 2.5 oz jar I add one heaping baby-food spoon amount of buttermilk powder, one heaping baby food spoon of Rep Cal Ultra fine calcium, one dropper full squirt of baby vitamins, just a hefty dash of probiotic powder, and enough Pediatric electrolyte to make the mix easy to squirt though a catheter tube with a syringe. I mix it all with a really small whisk in a drill, using it like your mom’s mixer for cake mix. Try hard not to blow up your snake. It is very rich and you do not need to feel a lump, which when done correctly, you won't. Don't over feed a sick snake. It may get better with just a couple of tube feedings, then offer the normal item.
Here’s pictures of each product I robbed off the web-
Gerber 2nd Foods Beef & Beef Gravy Baby Food 2.5 oz.
Generic picture of the Beef, but I usually use Veal, Lamb or Turkey flavor.

Rep Cal Ultrafine Calcium with D3
100% natural Oyster Shell phosphorous-free calcium carbonate with added Vitamin D3 to aid in the absorption of calcium.

SACO Buttermilk Powder
A Cultured Blend of Sweet Cream Churned Buttermilk, Sweet Dairy Whey, and Lactic Acid.

Enfamil Poly-Vi-Sol Multivitamin Supplement Drops 1.69oz.
Has an eye dropper-like bottle cap for easy dispensing.

NutriBac reptile probiotic, these microorganisms are suppose to be in your reptiles system. Often illness is a result of this balance being off due to stress, diet, etc. This stuff can help the animal “fix itself”. Read up on this stuff if you don’t know about it. I just use about a quarter teaspoon or less in the mix. A little goes a long way in the system.

Walgreens Pediatric Electrolyte Oral Maintenance Solution, Unflavored
Probably ends up being about five tablespoons, I just wing it with this ingredient.

Gerber baby spoons
Soft bite infant spoons, silicone coating
Maybe too much information, but somebody would probably want to know…

If this works for you, please share your experience here or send me an email, I would appreciate it. I am always looking for tweaks, too!