I have custom silicone tips for my IE8's. I also use custom earplugs (silicone) at work. I have had acrylic CIEM's in the past and now have the K10's. I haven't found there to be substantial differences between materials comfort wise or ease of insertion. Never used lubricant. One handy tip. To remove try just lifting the bottom of the CIEM with your thumb. Mine just pop straight out. HTH.