There is no way i can prove this but thought i would post a warning,our hen budgie devolved a problem with her throat,she was stretching her neck and opening her mouth giving signs to us she had a problem,she stopped eating and we rang the vet.
We dont have a avian vet and the one we rang said by all means bring her in but i may be of limited help,any way he concluded the same as us a throat problem but could not tell if it was a growth or something stuck.
We brought her home and for three days she never ate just drank water,got to the point she was just a ball of feathers in the bottom corner of the cage next to a light bulb we had put just outside the cage for warmth.
We never expected her to be able to last that long with out food,she doesnt like millet very much but my wife said we have some millet sticks with very tiny seeds on lets put one on the floor for her.
Tcut the story short she started to have the odd very small seed and now a week later she is her old sel nearly eating properly and as nosey and noisy as ever.
When we where looking at the iodine block we noticed the fixing wire was exposed due to her eating the block and the internal fixing wire was exposed,all the waxy paper that it is covered with was gone and as it doesn't degrade in moister we think it could have been what was stuck in her throat.
A picture of the type of block i mean showing the external part of the fixing wire.
6 x Small iodine blocks, cage bird products, cage bird health | eBay