The animal rights group, which wants the sport abolished, also co-ordinated demonstrations outside betting shops to coincide with the race, which took place at Aintree last Saturday.
In Swindon, female supporters in PVC dominatrix gear invited passers-by to see how they liked being whipped, alongside banners stating "Whipping doesn't hurt. Come and try it!"
Other activists carried placards and handed out leaflets outlining the number of horse deaths claimed in the organisation's report This Unsporting Life.
The report lists Aintree racecourse as second only to Cheltenham in a table of the deadliest courses in Britain.
The figures were released during the sixth Horse Racing Awareness Week, which was timed to coincide with the high-profile Grand National. Since 1997, 29 horses have died at the three-day meeting and eight during the race itself.
"The Grand National is, by design, a hazardous course that routinely results in horses dying," said Andrew Tyler, director of Animal Aid. "Many people around the world are amazed that such a punishing race is still permitted in a country that boasts high animal welfare standards. The time has come to dump it in the dustbin of history, along with hunting and cock fighting."
Tyler sent the report to the racing press as well as national and regional newspapers and broadcast media to expose what he described as "the dark side of racing".
The report says 30 per cent of annual racehorse deaths occur on race courses. The remainder are killed after incurring injuries in training or because owners no longer consider them commercially viable.
The Jockey Club disputes the findings, but Tyler challenged it to publish its own data, including the names of victims and details of the courses where they died.
The pressure group has also created a 90-second viral email film showing one horse falling during a race to put the report's statistics into visual context.