in theory the toys should be safe. no toy company is going to give a kid a toy with toxic paint. Things like gi-joe type action figures have a rubber band in the middle and most are held together with metal screws.
I'd pull them apart, re assemble with superglue and drop them in a Q tank with some guppies. if the guppies are happy after a week then no dramas.
unfortunately you can't make a omlette without breaking a few eggs. A little experimentation will give you a good eye for good and non fish safe decorations