You can't achieve leverage unless they fear you more, than they love Israeli money. Your non vote, doesn't scare conservative parties, if it did we would have achieved your leverage already. Instead 30%-40% of the electorate sits out every election, even more during midterms, which is the largest "political faction" already dwarfing both major parties. And has for decades.
Your leverage in that manner doesn't exist, it's a dead end. You want them to change, make them fear you. Your non-vote doesn't achieve that. A Viable Third Party would, but that takes time. So you only have a few options left to achieve your leverage.