Depending on individual cases there can be uses for such materials.

The god news is that these things are so cheap that you can buy a few and check them out. Worse case they can be novelties for the kids and even if they are complete junk your out very little.

If they have some nominal resemblance to useful they might serve for demonstrations and training. In one case, during a safety fair, a kiddie first-aid course was given for the 6 to 10 YO set. On stage EMTs wearing clown outfits acted out a kid falling and skinning a knee. They then demonstrated how to wash and dry the wound and apply a band-aid.

This isn't going to serve in a real mass casualty situation but the kids, many who are starved for attention, ate it up. This also freed up the adults so they could have a break.

After the demonstration an EMT applied gory wounds on arms and knees, a big hit with the boys, with a washable red magic marker, and the kids got to practice washing their hands, then the wound, and applying a band-aid. The plaster was a discount store variety that didn't stay stuck for long but in this role it served well enough.

Cheap space blankets are handy for training. Once you get used to how to prevent rips in training using the high quality ones is a breeze.

The discount light sticks could have a roll in night training. Their less reliable nature and weaker output would be good for training. When the real event happens your going to find working with the higher quality units easy.