Besides the fact that Dow Corning 111 Silicone Grease does a great job of sealing even the thinnest pneumatic leather (See: Testing Pouch Sealants), it has some very important advantages.

(1) Silicone cannot support life. And since it can't support life, it won't create an environment that's condusive to the growth of microscopic mold (fungi) or bacteria, which will rot the leather. (2) Silicone stays where it was put. It seals pouches best with the least changes over the years because silicone grease doesn't migrate. So, it won't saturate the wood over time.(3) It washes right off with Xylol, and it all comes off-- not just "most of it." (4) When it flows down into the pores of leather and carrier dries, the grease stays there. (5) It's just as greasy at absolute zero as it is at hundreds of degrees above zero. Its viscosity doesn't change with the weather! (6) Silicone grease has ZERO vapor pressure. It won't evaporate and then recondense in other parts of the player system.

NOTE: January 21, 2018: It has come to our attention that due to the changes in the chemical composition of modern lacquer thinner, Dow Corning 111 does not become homogeneous. To correct this problem, mix two grams of 111 with 1 fl.oz. of xylene (or xylol) and 1 fl. oz. of M.E.K. It will take about an hour for the grease to completely homogenized in the mixture -when well shaken at 15-minute intervals. For reference sake, 1 fl.oz. of liquid equals 2 tablespoons of liquid. NOTE: Your regular tableware tablespoon is NOT and actual tablespoon in size. Also, be sure to measure chemicals in metal or glass. Do not use plastic measuring devices.