Ever think of the fibers getting sucked up into the slot, hot lava water flowing and saturating thru them? Hole glides only seem to have very little of that, very uneven like. So holes are easier to push and dry a little quicker, slots clean, remove debris, and straightens out the fibers much better, in my opinion. If you have so much trouble pushing a slotted glide, you have overkill vacuum for single wanding, which forces you to use holes.