Well shoot, I could have sworn I read on here that what I did was a more common method! I thought it was sort of once they ate one rat, regardless of how you managed it, they'd more readily eat more rats. (Well, I'm still hoping that's the case.)
Well, I guess next time I'll change it up. I can't get anything smaller than small rats anywhere near me, I would have to order them (which is why I haven't yet, I'm waiting till he's consistently on small rats so I can order a bulk supply.) Though, he's so close to eating small rats I suppose I could order some and throw in a bag of rat pups as well. It'll have to wait till I get paid.
Next time I will leave the mouse totally out of the equation. I jumped the gun, I think, I was expecting it to be super hard so I inadvertantly made it super hard. This rat was nice and big, probably the biggest thing he's eaten to date, so maybe I will skip his next feeding and try with a rat again in two weeks.