Yeah mate, the big changer for me with the P valve system was when I started using little surgical alcohol swabs for cleaning up the old chap 20-30seconds before rolling the Rochester on, it’s like night and day the adhesion properties… the other trick I learnt was to have the “old chap” end of the p valve tube extra long and bent in to a “U” shape so the tube attaches straight and isn’t trying to breakaway at the weekend I shall get a photo and attach it on this post.