When my baby had the reovirus i had to force feed him too. I did not get any medicine or critical care food, so I improvised with chicken baby food. I know it wasnt the best, but at the time everywhere I checked had not received any shipments of the critcal care food and all online outlets were sold out.. =/ So I'm glad you got some and I hope it works!
Below is a quote from a previous post of mine to someone else who needed to know hhow to force feed a baby. I cpoied and pasted it.. hope it helps!
"As for feeding methods, getting a gecko to eat when they dont want to can be tricky. Some geckos will just open up their mouths when you brush the side with something, others (like mine) require force feeding when ill. First, try brushing her mouth with an appropriately sized cricket (held with tweezer/tongs) if she shows no interest after a few tries, then maybe try baby food. Thats the method Im currently trying.
You can use chicken baby food mash and mix about a teaspoon amount per feeding with calcium powder/leopard gecko vitamin powders (or critical care leopard gecko food if you can find some).
The two feeding methods you can try with this are 1. you can take a tiny bit on a spoon and place a small drop just beneath the nostrils (dont cover the nostrils though!) and see if she'll lick it off. If she does, repeat that for as long as she'll eat/till the teaspoon amount is gone. However, if she refuses to lick it off and wipes off her nose each time you place on a drop, then it may be time to force feed.
So, method 2. force feeding. This one is tricky, and im just learning it myself. But, the best method to this is to take the leo in your hand and hold her in your fist (fingers curled around her with her head poking out the top - you can use your thumb to apply pressure down on her as needed, but be careful!). Be sure not to squeeze her too much, it may take a couple tries to figure out how tightly to restrain her without hurting her. Also, do your best to make sure her back legs and tail are NOT being restrained! if she feels you are holding onto her tail/back legs tightly she may drop her tail to help free herself. Once you have her restrained (probably in your left hand) then you can take your right hand and gently slip the nails of your right-hand thumb and pointer-finger (like you are going to pinch her bottom jaw..but with your nailsin the side "slits" of her mouth..) into her mouth forcing it open enough to get the tips of your two fingers in on each side. But please be very very careful! She will bite at this point, it will hurt a little, but she probably wont be able to break the skin. To get the food into her mouth I need help - got someone to be ready to squirt a little food into its mouth as you hold her mouth open (I say squirt because I use a small syringe like "dropper" - i think its supposed to be for baby medicine?). Make sure you trust the person getting in the baby mash, because you can only put in small drops at a time, and the "tool" used to feed cannot be shoved into the mouth, just slightly slide the "tube-like" part in a small bit.
Its a tough thing to master, and im still learning myself. I hope this helped you though! Let me know if you find any better methods too!"
Sorry if thats a bit rough and hard to follow. I wrote that a few months back - and I had never had to force feed a baby until that time, so I was pretty frazzled about it.
Good luck!