i think the biggest problem is accidental poisoning. People poison mice and rats.

External parasites are no problem, because external parasites on rhodents are adapted to a hairy environment, they have claws to hang on to hairs and on a flat surface they stick out. They are vertically high, with all feets on the ground they are high and thin. Still rather flat, but in a different direction. Reptile parasites are vertically flat, and wide. Reptile parasites could not possibly attach to a hairy surface, they have the wrong shape.

That leaves internal parasites. Here i dont know anything.

i would take the mice, and keep them for 2-3 days, offering them water and appropriate rhodent food. If they dont die but thrive then they are unpoisoned, and then i would just go ahead and feed them. Internal parasites will often get killed by the digestive process, unless there are eggs that can resist the acids. And then it is still quite a leap from mammal to reptile.

Dead mice are of no use, and are in no way similar to frozen rats/mice from any halfway decent feeder breeder. If they live happily in your custody for a while it can be fine, except maybe for internal parasites, so its still a risk that maybe can be taken. But if they are dead, forget it, no way.