In most recipes I've seen, the ratio of corn syrup to candy melts or almond bark doesn't work at all. I only use about half the corn syrup the recipe calls for. Also, as soon as it's cool enough to handle, knead as much of the excess oil out as you can. Don't put it in the fridge - just let it set until it's cool. If you need it to be stiffer, mix it with fondant or gumpaste.