People usually make lotteries for 100% of the SBD.
To attract them, you need to gather twice the amount, or at least pay it off sooner than 1 week.

Your version is like just asking for votes on a regular post, but without the regular post itself.
Even if people can make a small winning, they still feel like you are cheating.

I don't have anything against that.
I am just explaining you why the interest is low.

(Also - make the people comment, and choose a winner that upvoted and commented. Only this way do you know it's not a bot)