Well, it won't cure anything. But use it for Ivy as if you had a cold and were using it for yourself. Maybe your mom or dad can help.

If Ivy is ok being in the bathroom with the door closed, that is a good place to "steam" him. Or in any smaller room; if he does freak out, maybe stay with him for 1/2 hour. (you will breathe it too, but that's ok)

I am suggesting this on the basis that it won't hurt his heart murmur or anything else. Please give your one vet a call and see if this is ok to do.