When you say 1/2 leather, where has the jelly been melted on the leather or the alancatera (spelling). If it has gone on the leather then it shouyld not be a major issue like johnny says a warm terry towel should removed maybe with a liitle APC. then treat and feed the leather i find liquid leather to be the best.
If on the other hand it has bonded to the alancatera just go careful, do not rub as you could bubble it also if you get it too wet your can run the risk of it going hard when it drys.