Pasty butt is a digestive disorder so you have to work from the mouth on down. The vaseline is to keep their little butts from getting too raw and cleaning daily is what you have to do. Are you feeding them olive oil or putting it on their bottoms? If feeding it to them; I'd stop.
Make sure that they are warm enough and that all other chick-care components are there; bedding, room to roam, fresh water, minimal handling, etc. Pasty butt is often a side-effect of stressed chicks.
Check bedding; when mine were babies, I had one that ate the shavings. His little crop felt like popcorn. They're not too bright and confuse the small sawdust type shavings with food. Change to bigger chips or straw. You may have to clean the straw a bit more often.
Do you put electrolytes in the water? It's a good idea but make sure that you read the instructions on the back. The packages come with enough electrolytes for a horse trough and you have to really dilute it.
At two weeks you might try a tiny amount of plain, fat-free, watered down yogurt to help with the digestive tract. Make sure that you get the kind with the probiotics and acidopholous and no sugar.
My babies were done with pasty butt after about a week from taking them home from the feed store. You're right in thinking that they should be over it by now.
Good luck, Mary