How about teaching them to recognise that "Steadyyyyyy!" means to slow down or take a little more care?

Nothing wrong with a well-timed "Oi!" though lolol.... but you could follow it up with a "Steady" to let them know what you do want. Comes in handy for other things too, especially if you want to do agility.

Wilbar - thanks, it's good to see the behaviour rationalised and what you have said is really what I want for my 2 and more or less what we do.

Merlins mum - I've unwittingly developed a kind of 'Woooooaaaaahhhhhh' which they seem to respond to and I can do it in a fairly casual voice still with a result.

It;s a great idea to get them to respond th whatever noise I make to stop them then do something calming with them once I have their attention.

I think that's the essence of it really, and a part of positive training. If you can't distract them, then it's only fair if you resort to Oi! or No! to show them what you would prefer instead. How else are they going to know? Seems so obvious doesn't it, but it surprises me how some people never consider that.