Do the CD/DVDs work well with normal radiation/particles?
I have some nasty strong radioactive stuff available (nothing too outrageous, NORM stuff, but hot, like 2 billion year old pitchbende) to try them with, and a stack of DVD discs.
DVDs are not that great because made of polystyrene that should be blend with fluorescent compounds in order to better absorb radiation energy. See e.g.
https://www.ncbi.nlm.nih.gov/m/pubmed/23353088/
For an inexpensive plastic scintillator, you may try PET instead. PET has excellent scintillation properties though its detection threshold is high, higher than the usual CR-39 and LR-115. See e.g.
https://aip.scitation.org/doi/pdf/10.1063/1.4890700
Meaning that at the end this will depend on what is your "nasty strong radioactive stuff".