Hate to say it but I've practically given up letting Archie off the lead. Like you say, he's brilliant at home, in garden, at puppy classes but out in the big world, no chance. I could turn cartwheels and I'm still not interesting enough no matter how many treats, games, praise I give him. Last time he shot off I only got him back because someone else managed to catch him. I agree its really embarrassing.

I now use extendable lead but it doesnt compare to him going exactly where he wants.