I like the idea that TFs should be vaguely within the realm of possibility. So I'm going to assume that my TFs that are caused by Latex/Costume/Suit/Goo will be viruses and nano-technology in a "dispersion gel." The viruses will take care of changing the DNA, while the nano-technology will maintain homeostasis during the TF, and the dispersion gel will keep everything organized. The virus needs the nano-technology to activate it, and the DNA can't cause viruses to reproduce, and will contain an enzyme that will remove anything that is not the final form's DNA. Also, another thing is that the nano-technology must verify every virus before it will activate it, and will not verify it if it has mutated in any way, even if it is just one DNA marker. Everything will be deactivated after the TF.

(I still want ideas and creative criticism.)