hob knob

I am desperate to find safety door knob covers for the oval doorknobs throughout our house.  The regular covers are too small and catch on the knob when turned, thus their efficacy is nil.  I have searched and searched online, and it seems that oval doorknobs have the baby safety industry stumped.  Really?  All they would have to do is produce an extra large knob cover.

I did find one site where someone claimed to have solved the problem.  Do you know what she did?  She replaced ALL the knobs in her house with round ones.

I am hoping someone out there knows how to fix my problem, without us having to replace all the knobs.  George opens every door in the house.  Then Hank follows him and shuts the door.  Yesterday they emptied Grace's dresser onto the floor.  Not only is it super annoying, it is also dangerous and I just can't believe it is so difficult to make an oval knob lock.

Any ideas?  Please, my sanity is at stake.