I saw some bottle top waterers for sale and immediately thought - WOW these would be great for Istinja Bottles. You could use them permanently in the bathroom on standard bottles or you could even place one in your purse and use as emergency Istinja cleaner with a normal bottle of water!
I had a standard large watering style can but this can be difficult for young children. These work great for young children and my 6 year old loves the idea as no more spills now!
The photo below shows what it is exactly that I used to make these bottles. Bottle Top Waterers which are available on Ebay and Amazon too!