To be honest with the lack of Nudges and Holds, along with the varying percentages it's probably not going to be the easiest thing to force, as there is no denying wins or features to mess up the percentages. So you can only take what it wants to give.
I stuck a few quid in it, reminded me of an OXO machine without holds or nudges to be honest, and it rolled in £20 so i left it alone not wanting to push my luck. (I was playing on 20p a go)
To be honest the fact it pays into your playing credits is rather evil in a pub or club, as if you're drunk imagine rolling in the 2k and not realising you could push collect at any time...