Never used that particular brand. Does it have instructions on the container? If so I'd follow them.
I usually use MicroSol. Get the decal in position, brush on MicroSol, watch the decal wrinkle horribly, try to ignore that (they do straighten back out), and do NOT touch it for an hour or so. If it still hasn't settled enough after it is dry another application of MicroSol will usually take it down some more.