A 20 seconds instrumental number can be heard playing on loop in the AKIHIDE “SOLO” LIVE NAKED MOON -Hadaka no Tsuki- website and it's the acoustic version of Ghost (Track 2 in Kikai Jikake no Yuenchi -Electric Wonderland-) :
http://akihide.com/special/naked_moon/
I think AKIHIDE should release an acoustic guitar album for his next solo release . If he can come up with a disc filled with acoustic guitar driven songs (ie. the 2nd disc in the special Musing version of Tsuki to Hoshi no Caravan) , I don't see why AKIHIDE can't do so as a standalone release