Home made is great, IF it is well made. If not, you could be taking a huge risk. I'm a big believer in making my own gear, but I recently abandoned the idea of making my own snake hook out of a thrift-store golf club because I don't weld, and I didn't want to discover the hardway that the glue or shallow threads or whatever I did, was weak. What if I'm handling a venomous snake and my hook fails because of a design or building flaw? It's not worth it. On the other hand, if you are willing to trust your safety to your skills (which we do every time we get behind the wheel for example) then go for it. Just make sure your skills are trust worthy. I didn't trust glue, but I would have trusted a weld, if I knew how to do that.
Home made bags are no problem of course, but thrift store pillow cases are cheaper and easier to deal with (but check and/or reenforce the corners!)
If I were in your shoes, and needed a lot of snake sticks cheap, I would build them as follows.
1. use hooks from the hardware store designed to suspend a bike from a rafter in the garage. They are stout and have a threaded end designed to screw into wood. You may want to bend them a bit to the shape of a real snake hook.
2. cut 1 1/4" - 1 1/2" dowels to length (36"?), sand them as needed, and drill the end to receive the bike hook.
You need to worry about the wood splitting on the end. Stress test it to see if you need to do anything to reenforce it. If you do I recommend finding a piece of brass or copper tubing, maybe an inch long, that is not quite big enough to slide over the end of the round dowell/stick (you may need to put the dowels on a lathe to make this true). Then you can use a propane torch to heat the metal ring, causing it to expand enough to fit over the wood. When it cools it will sinch down and really squeeze the wood. This is a hassle, but it would worrk well.
I still think you would be better off finding a source (mail order?) and getting each kid to drop the cash for one.