Well, I don't have enough energy to translate everything, but here are a couple of main points I jotted down. It's not organized, but hopefully you can get something out of it. A lot of potting materials used in Japan is probably not so available outside of Japan (or at least I don't know the source). This is an article from 2009.
Mr. Ikedo was pretty impressed by mixing "Bakuhan-seki" into his media. It's translated as Elvan, but I'm not sure if it is same. It is used for filtration of water, buffering pH, absorption of chemicals and bad smells in Japan due to porous structure. Mongolian stones are known to be high quality. I see some listed in Alibaba:
http://www.alibaba.com/showroom/bakuhanseki.html
Around 2000, people were talking about mixing in lime stones for some Paphs, but they stopped hearing about this topic. He thinks that bakuhan-seki could be better than lime stone.
Mr. Ikedo was using following mixed media for Polyantha and Parvi at least for 5 years:
1. Orchid Base: Asahi (beer company) was making some media for orchids. Basically they use the used-up Barley, press them into chunky shape, and burned at 700C. Here is how it looks like:
http://www.orchid.or.jp/orchid/society/paphio/news_2003_1203.htm
Basically charcoal-like material with slightly basic pH (7-7.5).
2. Neosofron: bark composted over several years (slightly acidic). I don't know the tree species, though, but it could be similar to orchiata. This is how it looks:
http://www.engei.net/Browse.asp?ID=71597
3. Bakuhan-seki
Ratio of the 3 components to be 5:3:2.
He thinks that the absorption of chemicals by Bakuhan-seki and slightly basic pH is beneficial for Parvi and Polyantha, and he sees lots of nice root growths (and he rarely see dead roots).
He also comments that using the clay pots (not same as the typical terra-cotta) shown in photo 2 are great to lower the root temp for the hot summer (for Parvi).
He hasn't tried this types of mix with Phal species (he has an amazing wild phals), but L. anceps seems to like this mix, too.
For deflasking, seedlings grow well for 6 months with sphag, but it needs to be repotted after a year or so. But he doesn't want to repot at least for 2 years for the seedlings, so he uses mostly tree fern chips or mostly orchid base (charcoal). But the charcoal is light, and the media can move around during the irrigation, so he mixes in 20% bakuhan-seki to stabilize the media. See photo set 5.
He likes this mix, but bakuhanseki is very expensive.
I have been keeping up with Mr. Ikedo's blog for the last couple years. He changes his potting media because some items become too expensive, or become not available. I'm not sure if he is still using this mix, though, since I haven't seen talking about it recently. Indeed, I thought that I read everything from his site, bud I didn't know about this hidden article which Mike dug up.