I would separate the dog and bitch, and only allow him to mate her once a day while she is receptive, which should only be for one or two days at a time during a heat. If yu let him continually mate her he could damage the bitch or himself and if she gets pregnant you could have a problem with premature puppies, as the sperm can live in the bitch for over a week, so when the first puppies are born there could be others not yet fully developed and therefore either be stillborn or need a lot of intensive care.
Not sure what you mean by pushing everything out, if you mean the sperm then some of it will enter the bitch even if they don't tie (lock up). You are overexerting this dog way too much and the bitch as well, its not fair to her as she cannot say no her hormones just tell her to let the dog mate her while she is ready.
To Boo - not everyone wants a dog that someone else has thrown out probably because of behavioural problems. Some people want particular breeds of dog for different reasons and responsible breeders will only breed when they have enough good homes for their puppies lined up and are willing to take back their puppies throughout their whole lives. I work for my breed rescue and very few are rehomed because of anything other than owners dying or getting too frail to cope with them.
Although many people do want rescue dogs, most seem to want young puppies that have no problems, and are not willing to take on anything that is a bit older or has problems, so they therefore go to breeders to provide exactly what they require.
The answer IMHO would be to licence all breeders and make it illegal to advertise puppies, they should only be sold after application to a breeder, the owner having passed an ownership test to prove they know what they are taking on.