I would be leaving it alone (and tell the parents not to continue at this time) back in diapers. Then in 3 weeks (two weeks IMO isn't long enough) I would only have panties and plastic pants on top at home. For success I tell my parents they need to do this. Daycare can be your choice. My choice is pull ups for two weeks. Not usually needed that long though. Just for sanitary reasons. I was just remembering I had a parent who had a very hard time with child peeing on toilet. Thing is they promised him something if he peed on toilet and the child would get something whether or not he did it. This was an eye opener and will tell future parents who do this that it shouldn't be happening if they want success. The child keeps getting what they want even though they don't use the toilet.