I'd check any freshwater forums for people with white worm cultures. Those might entice it as well.
I bought a wild mandarin a year and a half ago and started with culturing white worms. I stopped my culture at a certain point because it didn't need to be hand fed anymore since I have plenty of pods. I still hatch live baby brine about once or twice a week to feed other things and give a small pipette spray towards my mandarin with the pumps off.
I did something stupid with mine, I put it in observational "quarantine" and just ran prazi for flukes. Then at I think 6 days I put her in my backup 10g which has sand, rocks, softy corals, etc. I didn't run any other medication since I read their slime/mucus coat helps prevent ich. After two months there I put her in the display and haven't had any issues. In the quarantine tank, I didn't see her do much eating or anything either. It was a small risk to skip other steps, but I put her in a tank with more natural habitat features and she started eating then. I say it was stupid because I skipped a lot of protocol, but I only had one fish in the 10g at the time, however I still didn't want to put her in the display since I had fish I wouldn't want to lose.
Wilds can be finicky from what I've heard, but I've had nothing but smooth sailing after I had put her in the 10g. I also bought a rough looking mandarin because I thought she looked like she wouldn't make it in the LFS and I thought I could save her which I did. I did track down white worms the day I purchased the mandarin though.