I had clotted and useless Orange Seal after a couple years in a full bottle. The original bottle of Tufo sealant I got in Czech Republic lasted a lot longer in the bottle and still held inside the tire after many years (a tire designed to be repaired this way). I assumed the same would be true of other sealants until I read that they are temporary. But aside from that, I have to question the idea of repeatedly putting this junk inside a fine, lightweight tube in a $100 tubular. Are cyclists now so wealthy that they consider these tires disposable? Even a $30 tire, assuming you can find one. Is the idea of putting an extra tire under the saddle and doing a repair back home so unthinkable? I guess it goes along with paying someone to perform basic repairs and maintenance. What has happened to this sport?