I've currently got a mixed ability U9 team and I have one lad who's very much a toe-poker. The key for me is not to single him out as being 'wrong' but rather tailor the first part of training sessions around dribbling. This almost naturally encourages inside /outside step touches and then if we're on shooting/passing skills, just the odd gentle reminder to 'use your foot like you're dribbling/passing it'. I'm not saying he's stopped doing it now, far from it, but I can see him shaping his body differently and the potential 100% toepoking is down to mid 90s after a few weeks.

The 'penguin' feet walking/dribbling is great too.