I agree with your husband- you have tried the "teaching" approach, it is not working, if he is still lying. I would say, sit down and have a talk with him - he is 10, not a baby, not a toddler or preschooler, a pre-teen - he does need to start taking responsibility for his own choices and the consequences of those choices, including lying. Remind him that Thou Shalt Not Lie. is one of the 10 commandments ( if you are Christians or Jewish that should be a big deal), also tell him lying is not acceptable in your family, and remind him of the bigger consequences of lying - losing people's trust and confidence in you/your word, thus losing friends and supporters, also mention that sometimes, little white lies, or jokes, or stories can lead into bigger and bigger lies. Let him know that from now on , he will be dealing with the consequences of his own lies, you will not be rescuing him - if he lies and tells you his homework is done, and it is not, he will have to deal with the grade reduction - not get an excuse from you for the teacher(because that would be another lie BTW) - if he lies and says his chores are done, and they are not, he will get more chores to make up for it when you find out, or if he lies about other things that don't have a logical/natural consequence, you will not be able to trust what he says. Maybe read/talk about a version of the story "The Boy Who Cried "WOLF!" If he knowingly does something that is wrong, over and over, and you keep rescuing him and trying to "teach" him, it is obviously not working - natural consequences should work better.
I lied to my dad about something when I was about 7, I don't remember what it was, but it was a pretty big/important thing, not some little white lie/joke/story. Lying was a huge "offense" in our house. My parents had already/previously made that clear, through talks, and reading about lying when smaller things had happened, and the 10 commandments - the story "The Boy Who Cried Wolf." So, like your son, I knew lying was wrong, and I knew I was lying. The consequence was that for a period of time ( I don't know how long, but looking back to that 7 year old memory, it seemed like forever) my parents made a point of making sure they couldn't trust/believe what I told them anymore, because of that lie - they made sure if they asked me something, and I answered them, they would make a point in front of me, to check my answer with the other parent or another adult/teacher/babysitter/grandparent ( to make sure it was the truth) and not to just go on my word. It made a huge impact, and to this day ( I am 34) I CANNOT lie to my parents, and basically I am a very truthful person - I will occassionally avoid saying anything, if the truth will hurt someone, but I have never intentionally lied since that incident.
Good Luck!
Jessie