Onion Sacks... new use????

Ran across this and thought it might be useful to some. Someone suggested that you could use an onion sack... the loose netted ones.... during hatching to be certain to know which chick came out of an egg. Example... let's say you have a super dark Marans or super blue Ameraucana egg that you want for certain, and to know for certain which chick hatches from that egg. Maybe you won't be there during the hatch, etc. You just slip the egg in the onion bag and this gives the chick the ability to hatch but will not allow it to wander off from it's egg and will keep it contained until you can mark it for identification purposes.

Another person had also suggested a small sectioned off hardware wire box within the incubator.

Anyone ever try this? What do you all think? Do-able? Wise? Un-wise?