I had a tank raised that refused to host anything. I tried the pictures idea, the strainer idea too. Tried with frogspawn and 2 different BTA.
When I got the 150 I put in a wild caught one that was a little bigger. It hosted a carpet nem that night. Then I added a larger carpet and it hosted that. When I added the TR with the tank it instantly began hosting with the wild caught. Like instantly within 2-3min.
I also added a riteri which the larger clown left the carpet for, however the riteri would do fine, but as soon as the clown would host it would try to hide. Eventually the riteri didn't make it due to constantly going under rocks to get away from the clown. They both again host my carpet which when open is over. A foot wide. Never eaten any of my fish. I also do not have a DSB, in fact at night when it's just moonlights on, u can see light near the foot from the fuge light under the tank. The carpet has not moved in months and is doing great.