This is one of the methods to delay the enema start time (e.g. when you are bound).
You need the following (no "special " objects needed):
All you need is to freeze the water in the bottle(s) and when you are ready put them into the enema bag facing down. he tube should be long enough and prefilled with water (to remove the air). The ice will eventually melt down and slowly fill you up
To speed the process up you can use crashed ice instead of or in addition to the bottles.
The water will not be too cold, because the ice melts slowly and it will be enough time for the water to warm up a bit during the move through the tubings.
To view Aliexpress you might need to switch your mobile browser to the Desktop version.