France also, like the Mediterranean countries, ignore the "Asylum at first country of entry" laws and happily allow people to cross their country to get to UK. The way to stop people to europe in small boats is to insist all people picked up are returned to a port in the country they just left. They would soon get the message. Then they could apply to come to europe through the proper procedure.
The way EU citizens get round the 3 month rule is bt setting up private companies and sending their families out to work for the. Big Issue sellers are a case in point. The eastern European women you see selling those aren't homeless.