Washing our guys Toys depends on how dense they are. If they are stuffed, it's very hard to get them dried out, where mold/mildew won't get a start. Plus, it's hard to get all the soap out of Toys like that, and bleaching them is simply out of the question.
You really don't have to worry too much about Germs on them. Our guys are very capable of handling things like that, MUCH better than we are. I have Toys that are close to six years old, are still going strong. and played with regularly.
If it really bothers you, just toss them and buy new.
BUT, your guys won't like that