I'm a big fan of using words as sleep cues too (you can use them anywhere, don't have to remember to take them and they're cheap!). I used "sleepy time" too and still use it now that DD is 2. I also made it into a bit of a song. It goes like this:

Babies need a sleepy time, oh yes they do. Repeat x 3.
Mummies need a sleepy time. Daddies need a sleepy time.
Babies need a sleepy time, oh yes they do.

Used to sing that about 20 times. And funnily enough I've just started singing it again. Except now that DD is older she interrupts me and SHE tells me who needs a sleepy time such as Pooh, Roo, dolly, teddy, sissy etc. etc.

Also a big fan of a fluffy blankies. DD still has hers and she visibly relaxes when her head hits her fluffy blanky.

And don't worry if it takes longer to go from rocking to no rocking. I reckon it took a few months for us. But the rocking got shorter and I was more confident that it was actually going to work so it was less stressful.

DD got the hang of it in four days. Those four days were really tough. But it's really worth perservering. I do think the key is to rock them until they're sleepy and calm but not fully asleep and let them tip themselves over the edge.