How can I get my betta to use the betta leaf?

Okay my betta has been in a filtered one gallon tank for about 3 weeks and I begged my mother and she finally brought me a heated and filtered 5 gallon tank. Right now there's a silk plant a betta hammock and gravel in the 5 gallon and obviously water. The other silk plants and the cave/hideout...

I got the betta leaf hammock from PetCo. I actually thought this was the one without the metal piece since I didn't see it from the get go. I took the leaf out to clean it and noticed some brown residue (rust?) inside the rubber suction cup as well as rust around the plastic tip (almost looks...