Do you mean is Horn okay to stretch with? I think not. All materials besides piercings metals can be porous and iritable.

Stainless steel or glass has always been my choice...check here for cheap options:
www.painfulpleasures.com

I am going through this right now, and I've come across plenty of helpful info on the Internet, regarding materials safe for stretching. The obvious, more porous materials like wood, bone, stone, wouldn't be a good choice because of the bacteria issue and your body's healing. I've even heard that one shouldn't even use glass jewelry to stretch with... BOY it gets confusing! The majority says, use a safe metal that your body is okay with. After seeing a sight that sold a pair of stretchers made of horn, I went ahead and tried a tapered pair of horn earrings of my own, and my body is totally okay with it, and my skin is very sensitive. So really, it does just come down to being in tuned to your body, your body's make-up, & using good judgement. Your body will tell you if it doesn't like something - believe me! Again, this is just *my* experience. Found this, one of many blurbs online, hope it helps :) (When in doubt, ask a piercer you trust!)


"Materials

People react differently to different materials, so its important that you pay attention to what your body is telling you. If an item of jewelry that doesn't feel 'right' or a lobe is still hurting days after the stretch, take the jewelry out. Try a different material.
We have a lot of questions about which items are suitable for stretching and for fresh stretches, and as far as we're concerned there is no definitive answer. I know people who have stretched their ears with all sorts of materials (acrylic, wood, horn etc) without any problems at all. I also know people who have had problems when using surgical steel 316L for stretching. I know some people can react badly to wood.
It seems everyone is different in the way their bodies react to different materials.
I advise people that its their body and their own responsibility when using our products. At the first sign of any irritation remove the jewelry and replace with another material.
Speaking generally, of course the safest material to stretch with and wear in a fresh stretch would be surgical steel 316L. So surgical steel would be the most conservative approach.
However, bear in mind that people have been stretching their ears for thousands of years... Before any kind of steel was made."

source www.arka-shop.co.uk/acatalog...kits.html

dont use horn, its only recommended for use in HEALED piercings, and during a stretch a piercing is no longer considered healed!

i prefer glass, its usually less expensive than metals, and just feels better in my body.

that said, using a spiral is not a good way to stretch all the way to 3/4"! unless your ears are already just a size or two under that, that would just not be wise to try to do. it takes a very, very long time to get to that large of a size, and there should be long breaks between. the use of a spiral makes me think you might be in a hurry. i hope thats not the case, pleaaase take your time and be nice to your body!

Update: I bit the big one, and bought stainless steel earrings. Might'z well do it right. Thtthth$. Okay... I'm gonna say it again... *this is my last stretch*... ;)