With my Dart I used this to heave to: try to sheet the jib with the windward sheet. Or cleat it first, than make a tack, after the tack drop the traveller and turn the rudders to luff.
This sounds like the traditional method to stop a boat going upwind: tack without uncleating the jib, release the mainsheet completely and lock the tiller to leeward (like if trying to tack back). Most boats park.
