Does anyone know how to fill balloons full of large amounts of cream, foam, custard, gunge, etc?

Hoping to set the Mrs up so they get popped over her and want maximum mess!

This often 'pops' up, in fact it was the same question that broke my lurking 18 years ago...

1. Put substance in a large bottle.
2. Inflate balloon.
3. Put top of balloon over top of the bottle and let go, it will stay inflated.
4. Turn upside down and let the substance fall into the balloon, hold the neck. Sometimes squeezing the bottle helps.
An average balloon hold 4 liters of liquid.