The air bubble thing is a perpetuated myth,it doesnt happen.get you some good barber shears or very sharp scissors where you can basically cut straight up the stem exposing a huge amount of surface area,45 degrees is for beginners lol go for 15-20 degrees,simple to do with sharp scissors.Cuts need not be done under water believe me if that were the case most of us would have embolism's or anurism's sounds more like analism's to me lol