When all you have is a hammer everything looks like a nail :-D.
Except of course having a swiss army chainsaw there is more than
a hammer at our disposal. However, it surely cannot be too
difficult to later clean and pass other environment variables
as needed. Else one could say not clearing %ENV will
eventually bite you in the butt because you have no idea
what some clever author of an external program will rely
upon and do with an environment variable ;-).
--
perl -p -e "s/(?:\w);([st])/'\$1/mg"