And without knowing how it's routed, no one can say much of anything. If it's in-line (which would generally be unusual, but not "illegal" or anything if it's the only thing with that particular delay, assuming the track can handle the effect if it's a stereo delay on a mono track, etc.), then it's completely to taste. If it's on an auxiliary send (more typical), then you're pretty much defaulted to 100% wet, but the amount being sent to that aux is again, to taste.