[Lord Paul of Sheffield]

pellet pumps - half fill with pellets and cover with wateror flavoured liquid and the pumpaction forces waterin to the pellets and air out so floating pellets sink

It's a good way to do this - the other way is to soak pellets in water until they sink

Pellets pumps do the job in about a minutes - keeps goign until all the pellets sink -some will not first time -

And yet they do work