: Once the seal is tight, use vigorous up-and-down motions. The "pull" is often more important than the "push" as it loosens the debris.
You're looking for information on the "Sainsbury's Plunger"! sainsbury plunger
I'm assuming you might be referring to a specific product or service offered by Sainsbury's, a UK-based supermarket chain. After some research, I found a few possibilities: : Once the seal is tight, use vigorous up-and-down motions
If you are in the middle of a domestic emergency (i.e., a blocked loo) and live near an orange Sainsbury’s Local, this plunger is the cavalry. But is it a long-term tool, or just a single-use panic buy? Here is the breakdown. : Once the seal is tight