I disagree with "a taste of your own medicine" as being appropriate here, because it implies a level of revenge or, at the very least, a well-earned negative result against the "taster." A husband who asks his wife to take her own advice isn't being aggressive (though perhaps a bit stand-offish).
A better phrase for this is to "practice what you preach", which means to do whatever action you're suggesting of others.
Wife: Husband, the living room light is broken. We need to buy a new one.
Husband: Sure, honey. You're going to the market today-- practice what you preach and buy a new light.