id say you got the wrong clue, pull bouys are there for a number of reasons and one of them is to protect the back
we do not band pull dragging legs , all our group who use band are encouraged to fly kick .
if you want to get a sense of why pull bouys are so important
take a look at the best swimmers underwater , and you can see , how far even the great ones sink in the lower 1/2 of the body
nobody is flat on the water , accept salnikov whose stroke had his arse popping out the water ever time he drove his breathing arm in
however one can think , that this floatation could have come about by the old east german trick of inflating rectum with bike pump and use vaseline
to keep it there .
i kid you not , and so , if you don't like pull bouy , i have given you another alternative and all triathletes already have a bike pump .