City water is treated with chemicals and chlorine, and may contain trace minerals. Whereas distilled water has all the impurities removed. The tricide neo might somehow be effected by the chemicals or minerals in city water, perhaps changing its compostion. You can try using the trineo from your...
You have learned what I learned a couple of years ago about tricide neo. Yes, it will heal small bumblefoot in about a weeks timeframe. However, larger bumblefoot requires much more time to heal. I wont use tricide neo again, too time consuming. Minor surgery is the way to go for me.
Here's a link for you to read if you wish:
https://www.backyardchickens.com/t/513183/treating-bumblefoot-with-tricide-neo
Another link:
https://www.backyardchickens.com/t/303829/vet-suggestion-for-non-invasive-bumblefoot-cure#post_3725441