You know the makers - contact them and complain. Send it back and have it fixed or re-skinned. Frankly I think custom makers would rather have the opportunity to correct the problem than have their reputations brought into question on a popular forum like this. You can fiddle around with water and all sorts of oils but it won't remedy the basic underlying problem. At its loosest setting a tuneable skin should be quite slack and I am sure Seamus Keane intended this when it was made. They and you are victims of a rogue skin than was too fat-rich when fitted and has since dried excessively beyond remedy. By the time you have chased around buying and applying all this gunk you could have a new or re-skinned instrument. Above all, don't do what Bev suggests until you get a snub from the makers. If you mess with it yourself they will wash their hands of the problem. You can contact Keanes through the web. Search "Bodhran Makers". Whatever Catspaw may say, there are hundreds of them worldwide.