I researched the MSDS of the components of Milspec antifungus treatment a couple years ago and posted results in a discussion here on the board.
As I recall, it is not terribly toxic and the main ingredient is still used in special medical topical (skin) solutions today.
Mostly don't lick any components nor your hands after working with the radio. Wash your hands thouroughly, but then we always do that after handling anything with solder. Right?
Denatured alcohol (ethanol) is probably the best solvent, to minimized damage to components.
Henry Rogers at the Western Historic Radio Museum has a discussion on fungus treatment and a method he used to simulate application. You will have to dig around on his site. (for the life of me I see no reason to do this, but I'm not running a museum).
http://www.radioblvd.com/WWII-PostWar%20Hamgear.htm