Wilton candy melts suck. I say this a lot when answering posts about "my candy melts won't thin out!". Crisco is your best bet for now, but for future work, you'll probably need to invest in Paramount Crystals and higher quality candy melts such as Merckens or Guittard A'Peels.
Be sure you order the right product, NOT real chocolate that has to be tempered.
Here's a quick explanation from this website (p.s. I know nothing about this website, just liked the explanation)
"Chocolate companies created confectioner's coating so that we can avoid tempering real chocolate. In creating confectioner's coating, the cocoa butter was removed from the chocolate and palm kernel oil was added. The product looks just like real chocolate, but it cannot be sold with a chocolate label because it doesn't contain cocoa butter. Many companies make confectioner's chocolate taste really wonderful."
Here's a source with both products, but you can do a search to get the best prices for your needs.
Paramount Crystals: https://www.slice-heaven.com/store/show/76-320V