I chose a potty because my children are quite tiny. Even using the stool and insert for the toilet I have to help her up and I don't always have the time to do that when she needs to go.

As for dumping down the sink...gross!! lol. I dump it in my toilet and then use a clorex wipe to disinfect. It's no different than disinfecting the stool, insert and toilet handle between each use. I only have one child who uses the toilet so I do admit I don't disinfect every time she uses it, just at the end of the day.

I know this is for your own child so you can't do this but I always ask the parents what they use at home. Every child I have helped train so far has used the potty in the beginning as they all started early and are/were tiny. If a child only preferred one over the other than I would solely use that.