Girls, please. Just don't judge me beforehand. The child has scabs on …

Girls, please. Just don't judge me beforehand. The child has scabs on his head (we've had them for two months) and we were advised to apply vaseline to his head (yes, just vaseline, not vaseline oil). So I did, but it won't wash off ? After a day, we have a photo shoot ? What can I use to remove it?